FIRST ANNUAL POPULATION HEALTH
POSTER SESSION
SELECTED ABSTRACTS
The following are selected abstracts from the 2001-2002 Annual Poster
Session sponsored by the Population Health Program Student Organization.
Over 50 posters were presented. The abstracts included below demonstrate
the breadth and depth of faculty-student research collaboration typical of
the M.S./Ph.D. Program in Population Health.
Sleep Apnea and Endothelial Function
in a Large Community-Based Sample of Elderly Adults
Electromyography and
Magnetic Resonance Imaging in the Evaluation of Radiculopathy
Alcohol Education for Health Care Providers
Out-of-Pocket Price and Outpatient
Prescription Drugs among Elderly Americans
Geographic Disparities in
Population Health, and Disability. United States 1989-1991
Geographic
Disparities in Breast Cancer Screening In WI
Sleep-disordered
breathing and depression in the Wisconsin Sleep Cohort
Population-based
longitudinal study of menopause and sleep-disordered breathing
Practice Guidelines as Possible
Barriers to Quality Care: The Effect of Managed Care Involvement
The Association Between
Cardiovascular Disease and Cochlear Function in Older Adults
The Epidemiology of Bone Mineral Density in
Premenopausal Women with Type 1 (Insulin-Dependent) Diabetes: A Pilot
Study
Long Term Respiratory Parameters
in Very Low Birth Weight Children in the Surfactant Era.
Distributional
Concerns Expressed In Health Inequality Measurements
Newborn Screening With
Tandem Mass Spectrometry: Examining its Cost-Effectiveness in the
Wisconsin Newborn Screening Panel
Prevalence and Risk
Indicators of Neisseria gonorrhoeae and Chlamydia trachomatis
Infections Among Clients of Family Planning Clinics in Wisconsin
Does Implementation Of The AHRQ Smoking
Cessation Guideline In Primary Care Help Patients Stop Smoking?
Guiding Community Planning and Evaluation Efforts in
Tobacco Control: Predicting County-Level Rates of Smoking During Pregnancy
Regional hospital
organizational characteristics and surgical procedure rates
An Analysis of Multiple Causes
of Death Among Breast Cancer Cases in Wisconsin
Undiagnosed Obstructive Sleep
Apnea-Hypopnea Syndrome Leads to Excess Outpatient Pharmaceutical and
Medical Costs. A Bayesian Analysis of Population Data
Simulating the Epidemiology of
Breast Cancer in Wisconsin
The
Cost-Effectiveness of a Newborn Screening Program for Cystic Fibrosis
Sleep Apnea and Endothelial Function in a Large
Community-Based Sample of Elderly Adults
Nieto FJ,
Chair, Department of Population Health Sciences (formerly of Johns Hopkins
University)
Herrington
D, Robbins J, O'Connor G, Redline S.
Clinical studies in
small selected populations have suggested that sleep apnea may be
associated with endothelial dysfunction. We examine this association
among a subset of elderly participants in the baseline examination of the
Sleep Heart Health/Cardiovascular Health Study cohort (n=1250, age>70 yrs,
57% female). Indices of sleep apnea, derived from 12-channel home
polysomnography, were: the apnea-hypopnea index (AHI, average number of
apneas/hypopneas per hour of sleep) and hypoxia index (HI, %time below 90%
O2 saturation). Endothelial function was measured by B-mode
ultrasound of the brachial artery: flow-mediated dilatation (FMD, %change
in arterial diameter following reactive hyperemia). The Spearman
correlation coefficient of FMD with AHI and HI were -0.11 (p=.0004) and
-0.10 (p=.001), respectively. The magnitude of these correlations was
comparable to those between FMD and HDL (r=0.12) and carotid IMT (-0.12).
The age-sex-race-adjusted association between FMD and sleep apnea was
stronger among hypertensive individuals. Further adjustment for
cardiovascular risk factors (smoking, hypertension, serum cholesterol,
BMI), made the associations weaker and non-statistically significant,
although a borderline significant trend of decreasing FMD with increasing
levels of both AHI and HI was still present among hypertensives. The
results of this study do not support the existence of a strong independent
association between indices of sleep apnea and endothelial dysfunction in
older individuals in the community, although a weak association might be
present among older hypertensive individuals.
Electromyography and Magnetic Resonance
Imaging in the Evaluation of Radiculopathy
Frank J. Salvi, M.S. Alumnus
Radiculopathy,
presenting as neck or back and extremity pains, is often evaluated with
electromyography (EMG) and magnetic resonance imaging (MRI). The EMG
measures the physiologic integrity of the nerve roots, while the MRI
provides structural detail of the nerve roots and surrounding structures.
MRI is the more commonly utilized diagnostic test. The only study
comparing the two diagnostic tests found
|
EMG and MRI findings based on clinical syndrome |
|
Study
findings/correlation |
|
Clinical syndrome
Definite radic (n=25)
Probable radic (n=15)
Possible radic (n=7) |
EMG pos
18 (72%)
6 (40%)
2 (29%) |
MRI pos
15 (60%)
8 (53%)
4 (57%) |
Both pos
13 (52%)
3 (20%)
1 (14%) |
One pos
7 (28%)
8 (53%)
4 (57%) |
Both neg
5 (20%)
4 (27%)
2 (28%) |
EMG had better
positive and negative predictive value than MRI. Generally, EMG is
cheaper than MRI. Avoiding false positive studies also has the potential
to reduce interventional costs and serious complications in a disease
process with a fairly favorable natural history. There is significant
clinical variation in how EMG tests are performed and interpreted. To
help evaluate the goodness of the EMG test, an ROC curve should be created
based on expert rankings for the various criteria utilized in the
determination of a positive test. The impact of optimized but disparate
test results on decision-making should then be evaluated, and the clinical
outcomes of these decisions should be tracked.
Alcohol Education for Health Care Providers
Linda Manwell, M.S. Student
Judie Pfeifer, Outreach Specialist,
(Family Medicine)
Ellyn Stauffacher, Researcher, (Family
Medicine)
Michael Fleming, Population Health
Program Faculty (Family Medicine)
Objective:
While schools of medicine and nursing have made some progress in
implementing new educational, research, and clinical programs on alcohol
prevention and treatment, other schools have been less active in educating
their students or encouraging their faculty to work in the substance use
area. This project was designed to increase the teaching, clinical, and
research activities of faculty from multiple disciplines at the university
level. The overall goal was to change the university system -- not just
the individual course participants.
Methods:
The 15-month faculty development model included two 2-day courses held six
months apart, extensive pre- post- course evaluation, active mentoring,
development of a specific work plan for each participant, and meetings
with the leaders of the schools and universities. The interdisciplinary
model was structured on skills-based courses originally designed for
primary care faculty who had limited time and resources to develop
clinical, teaching, and research skills in a new area such as alcohol use
disorders.
Results: 153
participants completed the courses and 131 completed the 6-month follow-up
interview. Sixty-four designed teaching, clinical, or research projects
during the six-month period between the first and second courses. At the
6-month follow-up interview, 61% of participants reported clinical
teaching on alcohol, tobacco, or drug problems, 49% reported clinical
activities in this area, 36% reported conducting research, 32% percent had
sought additional training for themselves on AODA issues, 10% had
submitted manuscripts for publication, and 12% had submitted grant
applications. Pre- vs. post-course clinical scores from standardized
patient encounters showed highly significant improvements in screening,
brief intervention, and motivational interviewing among participants at
all sites (p<0.001).
Participants gave high scores to all
components of the faculty development model. Overall evaluations
indicated that 81% of the participants would repeat the training and 98%
would recommend the program to colleagues.
Conclusion:
This cost-effective faculty development program can serve as a model for:
1) increasing educational programs on substance abuse for students at our
public universities; 2) increasing faculty participation in research
activities in the alcohol area; and 3) increasing clinical programs
available in our university hospitals.
Out-of-Pocket Price and Outpatient Prescription Drugs
among Elderly Americans
Benjamin M. Craig, Ph.D. Student
This dissertation examines the effect of
out-of-pocket price on the acquisition of outpatient prescription drugs
among elderly Americans. Since the price effect likely varies by drug, I
have chosen to study antihypertensive agents, the most common class of
prescription drugs among Medicare beneficiaries (Waldron and Poisal,
1999). This dissertation aids in the debate on Medicare expansion and
furthers the health services research literature concerning economic
barriers to access.
Geographic Disparities in Population Health, and
Disability. United States 1989-1991
Abdelhani Guend, M.S. Alumnus
Karen Swallen, Population Health Program
Faculty (Sociology)
David Kindig, Population Health Program
Faculty (Pop. Health Sci.)
Disability Free Life
Expectancy was calculated for the 50 states and D.C. using the 1990 census
data, and the vital statistics. The results are presented in maps that
show the levels of adult longevity, and the percent elderly in the
population (top right panel). The states and D.C. are ranked based on the
percent of adult life expectancy with disability on the circular diagrams
where the rank is shown by the position on the radius and the magnitude as
an angle (in radians). Disability Life Years for Three types of
disability are used to map disparities between states (bottom right
panel).
Geographic Disparities in Breast
Cancer Screening In WI
Leann Andersen, M.S. Alumnus
Patrick L. Remington, Population Health
Program Faculty (Pop. Health Sci.)
Ron E. Gangnon, Researcher
Purpose:
To identify regional disparities in breast cancer screening in Wisconsin.
Methods:
Breast cancer cases were obtained from Wisconsin’s Cancer Registry by age,
ZIP code, stage, and year of diagnosis. The age-adjusted percentage of
cases diagnosed as Carcinoma In Situ (CIS), a proxy for mammography use,
was calculated for each ZIP code in the state of Wisconsin during three
time periods (1981-1986, 1987-1992, and 1993-1998.) Maps were created
showing the increase in percent CIS over time, and spatially smoothed to
reduce noise.
Results:
Between 1980 and 1998, the percentage of breast cancer case diagnosed as
CIS increased from 2 to 15 percent statewide, reflecting rapid growth in
mammography during this time. However, this increase was greater in urban
areas and areas with higher SES. Percent CIS by ZIP code is significantly
correlated with the proportion of residents living in rural areas (rho =
0.42), median family income (rho = 0.28), and percent of
college-educated residents (rho = 0.29.)
Conclusions:
Women residing in many rural areas of Wisconsin are still not receiving
adequate mammography screening. Mammography outreach and education should
be targeted to these areas.
Sleep-disordered breathing and depression
in the Wisconsin Sleep Cohort
Paul Peppard, Researcher (Pop. Health Sci.),
Ph.D. Alumnus
Terry Young, Population Health Program
Faculty (Pop. Health Sci.)
Mari Palta, Population Health Program
Faculty (Pop. Health Sci.)
INTRODUCTION: Based on clinical
observations, sleep-disordered breathing (SDB) is thought to be associated
with psychological depression but this hypothesis has not been tested. We
examined the cross-sectional relation between SDB and depression in the
Wisconsin Sleep Cohort Study, a population-based study of the natural
history of SDB.
METHODS: The Apnea-hypopnea Index (AHI, in events/hour), an indicator of
SDB severity, was determined by overnight in-laboratory polysomnography
sleep studies conducted on a sample of 1320 men and women. A subset of
805 of the 1320 participants had two sleep studies, both of which were
used in this analysis. Depression was assessed by the 20-item Zung
Self-rating Depression Scale and defined as a Zung score>50 (out of a
possible 100) or current use of antidepressant medications. Severe
depression was defined as Zung score>60 or use of antidepressants. Odds
ratios for categories of AHI predicting depression were estimated,
adjusting for age, sex, and body mass index. Other covariates were
examined including alcohol and tobacco use, education level and presence
of cardiovascular disease.
RESULTS: Relative to the reference category defined by AHI=0 events/hour,
the adjusted odds ratios (95% confidence intervals) for depression in the
higher AHI categories of 0<AHI< 5 events/hour, 5<AHI<15 events/hour, and
AHI>15 events/hour, were, respectively, 1.9 (1.2, 3.0), 2.9 (1.5, 5.5),
and 3.1 (1.6, 6.1). SDB was also a significant predictor of severe
depression.
CONCLUSIONS: SDB is a moderately strong predictor of depression,
independent of sex, age, BMI, and other factors. Since SDB is highly
prevalent, this finding, if representative of a causal association, may
indicate that SDB is responsible for a substantial population burden of
depression.
Population-based longitudinal study of
menopause and sleep-disordered breathing
Andrea G. Peterson, Researcher (Pop.
Health Sci.), M.S. Alumnus
Terry Young, Population Health Program
Faculty (Pop. Health Sci.)
Mari Palta, Population Health Program
Faculty (Pop. Health Sci.)
Laurel Finn, Researcher (Pop. Health Sci.)
We used longitudinal data to investigate
whether age-related increases in sleep-disordered breathing (SDB) are
accelerated by the onset of menopause, independent of body habitus
changes. Using a population-based sample of women enrolled in the
Wisconsin Sleep Cohort Study (WSCS), we investigated how the onset of
menopause during a four-year period accelerated the incidence of
polysomnographically determined SDB.
Practice Guidelines as Possible Barriers to Quality
Care: The Effect of Managed Care Involvement
Jessica Bartell, Ph.D. Student
Maureen
Smith, Population Health Program Faculty (Pop. Health Sci.)
Background:
Formalized practice guidelines are often provided to physicians in order
to decrease inappropriate variation in practice and improve quality of
care. Physicians, however, increasingly believe that these guidelines are
intended for cost-containment rather than quality improvement. It is
unknown whether the effects of practice guidelines on quality of care
differs for physicians with varying levels of managed care involvement.
Purpose:
We hypothesize that a
physician’s degree of involvement with a managed care organization
influences the impact of practice guidelines on quality of care.
Methods:
Data for this study is from the
1996-1997 Community Tracking Study (CTS), a nationally-representative,
telephone-administered survey of 12,528 non-federal, direct patient care
physicians who provide greater than 20 hours per week of patient care.
Managed care involvement was defined as the percent of revenue derived
from a physician’s largest managed care contract. The effectiveness of
practice guidelines was measured on a scale from 0=”No effect” to 5=”Very
large effect.” The dependent variable, physicians’ assessments of their
ability to provide high quality care, was measured on a scale from
1=”Disagree Strongly” to 5=”Agree Strongly.” Data were adjusted for
possible confounders using multiple linear regression.
Results:
59% of physicians reported that 25% or less of their revenue came from
their largest managed care contract; 32% of physicians received 26-49%;
and 10% received >50%. Physician practices had an average of 11.2 managed
care contracts (range 0-90). For physicians who derived less than 25% of
their revenue from their largest managed care contract, there was a
significant negative association (p = 0.001) between the impact of
guidelines on physicians’ practices and the quality of care physicians
felt that they were able to provide. For physicians who derived 25% or
more of their revenue from their largest managed care contract, there was
no relationship between the impact of guidelines and quality of care
(p=0.952).
Conclusions:
The data suggest that there is
a threshold of managed care involvement below which practice guidelines
create barriers to high quality care. One possible explanation is that
increasing physician involvement with a managed care organization makes it
more likely that underlying information and organizational systems are in
place that facilitate guideline implementation. Future research should
evaluate the importance of underlying care management systems in enhancing
the relationship between practice guidelines and quality of care.
The
Association Between Cardiovascular Disease and Cochlear Function in Older
Adults
Peter Torre III, Post Doctoral Researcher,
M.S. Alumnus
Karen J. Cruickshanks, Population Health
Program Faculty (Pop. Health Sci.)
Nondahl, D.M.,
Wiley, T.L.,
Gorga, M.P.
The prevalence of age-related hearing loss
is high among older adults. Cardiovascular disease and its risk factors
have been associated with hearing loss as measured by audiometry,
suggesting a possible role for atherosclerosis in the etiology of hearing
impairment. There have been no epidemiologic studies of the association
of cardiovascular disease and its risk factors with impairments in
cochlear function, one of the presumed sites of pathologic changes in
presbycusis. As part of the Epidemiology of Hearing Loss Study (EHLS) in
Beaver Dam, WI, distortion product otoacoustic emissions (DPOAEs), a
measure of cochlear function, were recorded in participants between 52-97
years of age. Of the participants (n=2626), 41% were men. DPOAE/Noise
ratios were recorded at 2000, 3000, and 4000 Hz. Self-reported history of
cardiovascular disease (angina, myocardial infarction (MI), and stroke)
was obtained in an interviewer-administered questionnaire. Individuals
with a DPOAE/Noise ratio average across the three frequencies < +9 dB and
no single frequency above +9 dB were defined as cases with abnormal
cochlear function whereas individuals with a DPOAE/Noise ratio average
> +9 dB and at least one frequency > +9 dB were defined as
controls. After controlling for age, gender, hunting, and activity level,
participants with a history of cardiovascular disease were 54% more likely
(O.R. = 1.54, 95% C.I. = 1.04-2.95) to have abnormal cochlear function.
Interestingly, individuals who exercised at least once a week were 32%
less likely (O.R. = 0.68, 95% C.I. = 0.50-0.94) to have abnormal cochlear
function than sedentary adults. After adjusting for age, sex, hunting,
and occupation, individuals with a history of MI were almost 80% more
likely (O.R. = 1.77, 95% C.I. = 1.03-3.06) to have abnormal cochlear
function as those without a history of MI. When this model was stratified
by sex, women with a history of MI were 2.7 times as likely (O.R. = 2.69,
95% C.I. = 1.19-6.07) to have abnormal cochlear function as women without
a history of MI whereas for men, history of MI was not a significant
predictor of cochlear function. Neither self-reported history of angina
or stroke were significant predictors of cochlear function. These results
provide preliminary support for the association between cardiovascular
disease and abnormal cochlear function, particularly for women with a
history of MI.
The Epidemiology of Bone Mineral Density in
Premenopausal Women with Type 1 (Insulin-Dependent) Diabetes: A Pilot
Study
Kirstie K. Danielson, Ph.D. Student
Catherine Allen, Population Health Program
Faculty (Pop. Health Sci.)
There is
conflicting evidence as to the prevalence and degree of decreased bone
mineral density in individuals with type 1 diabetes. Research on the
long-term complications of decreased bone density in type 1 diabetes is
also contradictory. Studies have shown both increased and similar rates
of fracture in individuals with type 1 diabetes compared to individuals
without diabetes. A pilot study has been undertaken to determine the
feasibility of a large population-based epidemiological study on bone
mineral density in premenopausal women with type 1 diabetes. Participants
for the pilot study are currently being recruited through the Madison-area
Diabetes Clinics. Data on heel bone mineral density, endogenous and
exogenous estrogen, glycemic control, diabetes duration, smoking, physical
activity, diet, adiposity, and demographic characteristics are being
collected. Twenty premenopausal women between the ages of 18 and 45 will
be studied. Information collected in this pilot study will provide the
foundation for a future case-control study on the prevalence and risk
factors for low bone density in a representative sample of women with type
1 diabetes. Information derived from this area of research could
ultimately help doctors identify women with type 1 diabetes at risk for
low bone density and allow for earlier detection and treatment.
Long Term Respiratory Parameters in Very Low Birth
Weight Children in the Surfactant Era.
Hana Said, Ph.D. Student
Mari Palta, Population Health Program
Faculty (Pop. Health Sci.)
Mona Sadek-Badawi, Researcher (Pop. Health
Sci.)
Kathleen Madden,
Aggie Albanese, Researcher (Pop. Health
Sci.)
Christopher Green
Exogenous surfactant
use in premature neonates improves early respiratory status and survival.
Surfactant was experimental prior to 8/1/1989, an investigational drug (IND)
from 8/1/1989 and released 8/1/1990. Pre surfactant studies of very low
birth weight (VLBW) children have uniformly shown lung function
impairment. Long-term respiratory function, especially in those born
after 8/1/1990, is not well described. The new treatments and greater
prematurity may have led to fundamental changes in neonatal lung disease (Jobe
and Bancalari, 2001). For this study, the authors obtained respiratory
parameters at age 10 by the handheld Jaeger AM1. Subjects were a regional
cohort of 193 VLBW children and controls 267 Wisconsin school children.
The VLBW cohort was born 8/1/1988- 6/30/1991, spanning pre-surfactant
(T1), IND (T2) and post-surfactant (T3) eras. FEV1 in the controls was
close to predicted, but significantly lower in subjects (observed/
predicted ratios 0.97 and 0.86 for controls and VLBW, p<0. 0001). FEV1
was most compromised in VLBW children with bronchopulmonary dysplasia
(BPD) (ratio: 0.81, 95% CI: 0.78, 0.84) by Bancalari criteria. FEV1 did
not improve between births during T1 to T3. VLBW children with BPD had
FEV1 ratios of 0.85, 0.78 and 0.82 for T1, T2, T3, respectively. These
ratios were lower (p <0.001) than for VLBW children with no neonatal
respiratory disease of 0.88, 0.91, and 0.91. The authors further explored
the characteristics of respiratory disease in VLBW children with BPD as
reflected by other parameters. The lack of improvement in FEV1 across time
and the respiratory parameter patterns with BPD point to an irreversible
component of recent BPD that may be explained, in part, by the disruption
of alveolar septation and the increased survival of smaller infants
associated with the use of exogenous surfactant.
Distributional Concerns Expressed In
Health Inequality Measurements
Yukiko Asada, Ph.D. Student
To examine how unequally health is
distributed within a population, a variety of measurements of health
inequality have been routinely used. They include but are not limited to:
range measures, the Gini coefficient, and the World Health Organization
(WHO) health inequality index. Whatever health measure, unit of analysis,
and unit of time researchers use for their analysis for health inequality,
summarizing the extent of inequality in a health distribution by means of
a single number is an strategy to facilitate examination, comparison, and
understanding of health inequality in question.
How should
researchers choose among various health inequality measurements
available? These decisions have often been driven by convenience rather
than principle. But different measures can conclude different degrees of
health inequality even when used for the same health distribution.
Researchers must know how to select an appropriate measure and what a
measure, however selected, is telling them about health inequality.
This project proposes
a framework for investigating distributional concerns expressed in health
inequality measurements. Adopting relevant analyses from philosophy,
economics, and health literature, I propose to investigate distributional
concerns under seven key points: (1) unit of analysis, (2) the way
comparison is made, (3) distance concept, (4) aggregation methods, (5)
sensitivity to the mean, (6) sensitivity to the population size, and (7)
subgroup consistency and decomposability. Answers to these five questions
can be drawn from philosophical justifications, epidemiological findings,
and policy relevance. My analysis is primarily philosophical, but when
appropriate, I refer to the empirical approach, i.e., people’s perceptions
of distributional concerns, taken by, for example, the WHO. This research
will be valuable as guidance for anyone who conducts and interprets
empirical analyses of health inequality.
Newborn Screening With Tandem Mass
Spectrometry: Examining its Cost-Effectiveness in the Wisconsin Newborn
Screening Panel
Ralph P. Insinga, Ph.D. Student
Ronald H. Laessig, Population Health
Program Faculty (Pop. Health Sci.)
Gary L. Hoffman
Objective:
To examine the cost-effectiveness of tandem mass spectrometry (MS/MS) in a
neonatal screening panel for 14 fatty acid oxidation and organic acidemia
disorders in the Wisconsin Newborn Screening Program.
Study Design:
Incremental cost-effectiveness (C-E) analysis using a hypothetical cohort
of 100,000 infants. First, the cost-effectiveness of screening for
medium-chain acyl-CoA dehydrogenase deficiency (MCAD) alone is analyzed.
MCAD represents the most comprehensively studied disorder on the panel,
and that expected to yield the greatest fraction of screening benefits.
Because screening costs for adding other disorders to the panel are
minimal, a threshold of $50,000/QALY (quality adjusted life year) is used
to determine whether screening for MCAD alone is cost-effective, or
whether data on additional disorders would need to be incorporated into
the analysis to arrive at a conclusion regarding the overall
cost-effectiveness of MS/MS. Sensitivity analyses are performed on key
cost, incidence and outcome variables.
Results:
Under very conservative assumptions, screening for MCAD alone yields an
incremental C-E ratio of $41,862/QALY. Employing more realistic
assumptions, screening becomes even more cost-effective ($6,008/QALY), and
remains cost-effective so long as a neonatal diagnosis is at least 36%
effective in reducing MCAD morbidity and mortality or the incremental cost
of screening remains under $13.05/test. Adding the incremental costs for
detecting the other 13 disorders on the screening panel still yields a
result well within accepted norms for cost-effectiveness ($15,252/QALY).
Conclusions:
In Wisconsin, MS/MS screening for MCAD alone appears cost-effective. With
nationwide screening, it is estimated that 20-30 MCAD related neonatal
deaths could potentially be prevented annually. Future analyses should
confirm the effectiveness of a neonatal diagnosis in preventing morbidity
and mortality and examine the cost-effectiveness of alternative follow-up
and treatment regimens for MCAD and other panel disorders.
Prevalence and Risk Indicators of
Neisseria gonorrhoeae and Chlamydia trachomatis Infections
Among Clients of Family Planning Clinics in Wisconsin
John R. Pfister, Ph.D. Student
Lori A. Amsterdam,
Joanne Rombca,
Roberta A. McDonald,
Jeffrey P. Davis. Population Health
Program Faculty (Pop. Health Sci.)
Chlamydia
and gonorrhea are the two most commonly reported sexually transmitted
diseases in Wisconsin. These infections are often
asymptomatic and may lead to serious sequelae such as pelvic inflammatory
disease, ectopic pregnancy, and infertility. The use of selective
screening criteria to target laboratory testing to individuals at highest
risk of infection has been shown to be an efficient and cost-effective
strategy for the control of chlamydia, and may prove useful for
gonorrhea as well. This study was conducted to determine the prevalence
and risk factors for acquiring gonococcal and chlamydial infections among
clients seeking health care services in urban and rural family planning
clinics in Wisconsin. From these data, selective screening criteria for
gonorrhea will be developed, and the current criteria for chlamydia
will be re-evaluated.
Does Implementation Of The AHRQ Smoking
Cessation Guideline In Primary Care Help Patients Stop Smoking?
David Katz, Population Health Program Faculty (Pop. Health Sci.)
D Muehlenbruch,
Randall Brown, Ph.D. Student
M Fiore, Population Health
Program Faculty (Medicine)
Timothy Baker, Population
Health Program Faculty (Pop. Health Sci.)
BACKGROUND: The
Agency for Healthcare Research and Quality (AHRQ) Smoking Cessation
Practice Guideline recommends systematic assessment of smoking status and
counseling of smokers at every visit, but the feasibility of implementing
the guideline and its actual effectiveness in clinical practice are
unknown.
METHODS: We
conducted a randomized controlled trial in 8 primary care clinics of a
guideline-derived intervention (nurse training on use of modified vital
signs stamp, proactive telephone counseling plus free nicotine replacement
therapy (NRT)). After baseline data collection (6/99-6/00), the
intervention was implemented in 4 test clinics (6/00-5/01); patterns of
usual care were observed concurrently at 4 control clinics. We obtained
exit interviews of 2164 consecutive adult smokers who presented for
routine, non-emergency care and agreed to follow-up. Abstinence (no
cigarettes over prior 7 d) was determined by telephone interview.
Follow-up at 6-mo was 87 and 89% complete at test and control clinics,
respectively. We used hierarchical logistic regression models to
determine the effect of the intervention on cessation outcomes, after
adjustment for patient-level covariates (e.g., age, gender, cigarettes per
day).
RESULTS:
Concordance with guideline recommendations was significantly greater at
test clinics during the intervention vs. baseline periods; negligible
changes in concordance were observed at control clinics. Compared to
control smokers, a significantly greater proportion of test smokers made a
quit attempt or stopped smoking during the intervention period (Table,
*p<=0.05). In addition, test smokers who were still smoking at 6-mo
follow-up tended to be more likely to have a plan to quit than control
smokers (OR 1.3, 95% CI 0.9-1.8). There were no significant differences
in cessation outcomes between test and control smokers during the baseline
period.
|
|
Baseline Period |
Intervention Period |
|
|
Control
(n=510) |
Test
(n=513) |
Adjusted OR
(95% CI) |
Control
(n=499) |
Test
(n=642) |
Adjusted OR
(95% CI) |
|
Any quit attempt, % |
41 |
44 |
1.1 (0.9-1.5) |
50 |
57 |
1.4 (1.0-1.9)* |
|
2-mo quit rate, % |
5.1 |
5.3 |
1.0 (0.6-1.8) |
5.8 |
16.4 |
3.3 (1.9-5.6)* |
|
6-mo quit rate, % |
8.6 |
7.8 |
0.9 (0.6-1.4) |
9.8 |
15.4 |
1.7 (1.2-2.6)* |
CONCLUSION: Nurse-based implementation of the AHRQ smoking cessation
guideline significantly increased quit rates by focussing attention on
smokers who are interested in quitting. The 6% absolute difference in
6-mo quit rates associated with this intervention is similar to that
observed in clinical trials of NRT. Effective reduction of tobacco use
requires redesigning health care systems to improve the delivery of
cessation advice and pharmacotherapy to properly selected smokers in a
time-efficient manner.
Guiding Community Planning and Evaluation Efforts in Tobacco Control:
Predicting County-Level Rates of Smoking During Pregnancy
Vanessa H. Newburn, M.D./Ph.D. Student
Patrick L. Remington, Population Health
Program Faculty (Pop. Health Sci.)
Paul E. Peppard, Researcher (Pop. Health
Sci.), Ph.D. Alumnus
Effective tobacco control programs at the
local community level are critical for statewide impact. However, there
are few methods available for setting goals and evaluating effects at the
local level. The purpose of this research was to develop and illustrate
the application of a method that models historical trends in tobacco use,
predicts future prevalence of use, and uses predictions to set
community-specific goals. The study used locally available (and
underutilized) data on the prevalence of smoking during pregnancy recorded
on the U.S. Birth Certificate for the years 1989 to 2000 in Wisconsin.
Trends in prevalence for all counties (n=72) and the State were modeled
using linear regression of log of prevalence on year (R^2= 0.98, State).
For the State, smoking prevalence declined from 22.9% of pregnant women
(1989) to 16.5% (2000), an annual (relative) rate of decline of –3.3
percent per year (95% CI [-3.7, -2.9]). Among counties, there was
considerable variation in both prevalence of smoking (7.5 to 53.5%) and
relative rate of change (-5.5 to 1.6 percent per year). Nearly half of
all counties showed rates of change significantly different from the
State. Local variation suggests that goals should reflect
community-specific trends. We suggest that communities use the above
method to describe trends, apply the model to predict a future rate based
on trends, and set goals according to a percentage of the rate predicted
by historical trend analysis.
Regional hospital organizational
characteristics and surgical procedure rates
Nilay D. Shah, Ph.D. Student
Maureen A. Smith, Population Health
Program Faculty (Pop. Health Sci.)
Research Objective:
Appropriate distribution of hospital services across regions may improve
the efficiency and quality of heath care delivery. However, little is
known about the organizational characteristics of hospitals within
referral regions and the association between these characteristics and
utilization patterns. The goal of this study is to 1) characterize
hospital organizational characteristics (i.e. specialization,
centralization, and integration), 2) to describe the
average organizational characteristics of hospitals within referral
regions, and 3) to relate these organizational characteristics to the
rates of six common surgical procedures within these regions.
Study Design:
Hospital level data were obtained from the 1999 American Hospital
Association (AHA) Annual Survey. Three scales reflecting the extent of
hospital specialization, centralization, and integration were created
based on a modified version of Bazzoli, et. al., scales for health systems
and networks (Health Services Research 1999;33:1683-1717). Data on
hospital referral regions (HRRs) and the rates of six common surgical
procedures in non-HMO Medicare enrollees were obtained from the Dartmouth
Atlas. The mean hospital specialization, centralization, and integration
were calculated for all hospitals within each HRR. The rates of these
inpatient surgical procedures for HRRs were regressed on specialization,
centralization, and integration. The unit of analysis was the HRR.
Population Studied:
4184 general medical and surgical hospitals that completed the 1999 AHA
Annual Survey, and 306 HRRs included in the Dartmouth Atlas.
Principal Findings:
The average specialization, centralization, and integration across
hospital referral regions were 38.2% (s.d.=7.7%), 5.0% (s.d.=5.1%), and
3.2% (s.d.=3.0%), respectively. Increased specialization was associated
with lower rates of cholecystectomy, back surgery, and radical
prostatectomy, but a higher rate of colectomy. Increased centralization
was associated with a higher rate of lower extremity bypass and a lower
rate of cholecystectomy. Increased integration was associated with higher
rates of colectomy, hip replacement, and radical prostatectomy, but a
lower rate of back surgery. The extent of variation for the six surgical
procedures was calculated using the ratio of highest to lowest procedure
rates by HRRs. There were no consistent trends in the relationship of
organizational characteristics to procedure rates from low variation to
high variation procedures.
Conclusion:
Hospital organization characteristics across hospital referral regions
were associated with surgical procedure rates. In general, average
regional specialization was associated with lower procedure rates and the
average regional integration was associated with higher procedure rates.
There was no obvious trend in association between average regional
centralization and procedure rates. Optimal organizational
characteristics of hospitals across regions remain to be determined.
Because we assess the ecologic association between mean hospital
organizational characteristics in a region and rates of surgical
procedures, future analyses should evaluate these relationships more fully
at the level of individual hospitals.
Implications for
Policy, Delivery, or Practice:
Regional hospital organizational characteristics, surgical procedure
rates, small area variation.
An Analysis of Multiple Causes of Death Among
Breast Cancer Cases in Wisconsin
Indiana M. Strombom, Ph.D. Student
Patrick L. Remington, Population Health
Program Faculty (Pop. Health Sci.)
Amy Trentham-Dietz, Population Health
Program Faculty (Pop. Health Sci.)
Stephanie Robert, Population Health
Program Faculty (Pop. Health Sci.)
John M. Hampton,
Polly A. Newcomb, Researcher
Given the declines in breast cancer
mortality experienced in the state and the nation, we analyzed differences
in the distribution of causes of death- underlying, antecedent and other
significant causes- among Wisconsin women who had a diagnosis of invasive
breast cancer. Cases were participants in a population based,
case-control study, diagnosed between 1988 and 1994 (n=7,250). We
passively followed them through 1999 or until the death outcome was
ascertained through state vital statistics or NDI match. We characterized
women into subgroups according to whether the underlying cause of death
was breast cancer or another cause. We further analyzed the
characteristics of women who died of an underlying cause other than breast
cancer, according to whether this disease is mentioned anywhere in the
death certificate, or not. Chi-square tests and log linear models were
used for various subgroup analyses.
Most of the women with breast
cancer died of their disease (59%). One third of the breast cancer cases’
death certificates have no mention breast cancer. When not listed as UCOD,
any mention of breast cancer in the death record was related to case and
tumor characteristics associated with shorter interval lived after
diagnosis. Contrary to our hypothesis, mention of breast cancer was not
associated with differences in the distribution of UCOD’s. Of interest is
the 15% of cases that died of second primary tumors, many associated with
breast cancer, where 89% have no mention of breast cancer in their death
certificates.
Undiagnosed Obstructive Sleep Apnea-Hypopnea
Syndrome Leads to Excess Outpatient Pharmaceutical and Medical Costs. A
Bayesian Analysis of Population Data
Grace E. Flood, Post-doc(Pop. Health Sci.)
Dennis G. Fryback, Population Health Program Faculty (Pop.
Health Sci.)
Marjorie A. Rosenberg, Population Health Program Faculty
(Pop. Health Sci.)
Terry Young, Population Health Program Faculty (Pop. Health
Sci.)
Background.
Previous studies have shown that
undiagnosed, untreated sleep apnea increases medical care utilization and
costs. These studies were case-control in design, thus subject to
selectivity bias, and were uncontrolled for body mass index (BMI).
Objective.
To estimate annual outpatient
pharmaceutical and outpatient medical costs associated with undiagnosed
obstructive sleep apnea-hypopnea syndrome (OSAHS) that may exceed those of
persons without OSAHS.
Design.
Population-based cohort study.
Setting and Sample.
A probability sample of 581 State of Wisconsin employees studied by
polysomnography.
Measurements and
method. Utilization by
persons with and without undiagnosed OSAHS (1481 person-years) was
determined retrospectively from insurance records. Annual outpatient
pharmaceutical and medical utilization occurring in 1992-1994 was valued
in 1996 dollars. A two-part econometric cost model was fit using Bayesian
methods.
Results. Controlling for age, BMI and
smoking status, males with undiagnosed OSAHS had a 68% probability of
excess annual outpatient pharmaceutical costs (mean excess = $568; median
= $109) and a 60% probability of excess annual outpatient medical costs
(mean excess = $376; median = $124). A female with undiagnosed OSAHS had
a 67% probability of incurring excess annual outpatient pharmaceutical
costs (mean excess = $893; median = $145) and a 59% probability of
incurring excess annual outpatient medical costs (mean excess = $502;
median = $161).
Conclusions.
Persons with undiagnosed OSAHS
are likely to incur excess outpatient pharmaceutical and medical costs
compared to persons without OSAHS. We demonstrate viable analytic methods
for studies where individuals can incur zero costs with a substantial
probability.
Simulating the Epidemiology of Breast Cancer in
Wisconsin
Dennis G. Fryback, Population Health
Program Faculty (Pop. Health Sci.)
Marjorie A. Rosenberg, Population Health
Program Faculty (Pop. Health Sci.)
Patrick L. Remington, Population Health
Program Faculty (Pop. Health Sci.)
Amy Trentham-Dietz, Population Health
Program Faculty (Pop. Health Sci.)
Natasha K. Stout, Ph.D. Student
Lorne M. Tappa, Researcher
Breast cancer mortality rates
have been steadily declining in
Wisconsin over the past decade,
from 29/100,000 to 23/100,000, with a similar trend in the US generally.
Utilization of screening mammography, improvements in treatment and
changing demographics and risk factors have been posited to explain this
decline but the effects of each are as of yet unknown. Our project seeks
to understand the relative contributions of screening, treatment and risk
factors to explain trends in breast cancer incidence and mortality in
Wisconsin. To examine these factors we use a computer model that
simulates the epidemiology of breast cancer. This novel method uses
theory and data from many disciplines and sources to generate population
level statistics about breast cancer incidence and mortality in
Wisconsin. By varying model inputs, hypotheses about the contributions of
screening mammography and treatment to reducing breast cancer mortality
can be explored. Currently we are calibrating our model to population
statistics from the Wisconsin cancer registry. Once calibrated,
researchers and policy makers can use the model to explore policy
alternatives in the prevention and treatment of breast cancer.
The Cost-Effectiveness of a Newborn
Screening Program for Cystic Fibrosis
Natasha K. Stout, Ph.D. Student
Humaira Nizamuddin,
Surachat Ngorsuraches
Purpose:
We investigated the cost-effectiveness of a newborn cystic fibrosis (CF)
screening program for an average birth cohort in Wisconsin using
prospective randomized trial data from the same population. The evidence
for effectiveness of early intervention for CF is limited and
controversial, yet routine screening for CF is performed in several states
including Wisconsin. To date cost-utility analyses have focused on
prenatal screening for carriers of CF and not on newborn screening for the
disease.
Methods:
We used a decision-analytic approach incorporating a determinstic model of
stages in CF disease progression. The model of disease progression
accounted for differences in the rate of lung function decline and life
expectancy within a CF population. An incremental cost-effectiveness
analysis compared three alternatives: screening using the Immunoreactive
Trypsinogen (IRT) test, screening using the IRT test in combination with a
DNA test, and no screening. A societal perspective was assumed.
Results: Under a
base case assumption that screening leads to moderate short-term benefits
by slowing the rate of decline in lung function, our initial model shows
that the cost-effectiveness ratio for IRT screening compared with no
screening was $328,444/QALY. The IRT/DNA test combination produces more
accurate test results compared with the IRT test alone but is more costly
resulting in an cost-effectiveness ratio of $678,806/QALY for screening
using the IRT/DNA test combination compared with IRT test alone. If we
assume a one year increase in life-expectancy gained from lead time by
screening, then the cost-effectiveness ratios decrease to $46,407/QALY for
the IRT test compared with no screening and $83,929/QALY for the IRT and
DNA test combination compared with the IRT alone. The model results are
highly sensitive to assumptions regarding the benefits of screening
effectiveness. Because of the controversial nature of the evidence for
screening effectiveness, this parameter is also the most uncertain.
Conclusions:
At present, insufficient evidence is available on the effectiveness of
early intervention of CF to make a definitive conclusion as to the
relative cost-effectiveness of a screening program. This suggests that
long-term studies on the effectiveness of screening and early intervention
are needed to make informed policy decisions about the implementation or
continuation of a screening program for CF; long-term results from the
randomized trial in Wisconsin should prove decisive. While our analysis
is specific to Wisconsin, the model is readily generalizable to other
populations.
