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Derek S Brown

Publications and source records attributed to Derek S Brown.

10 recordsLinked to original sources
PubMed2005

Effects of changes in self-reported vision on cognitive, affective, and functional status and living arrangements among the elderly.

PURPOSE: To study effects of changes in self-reported vision on functional status, cognition, depressive symptoms, and living arrangements. DESIGN: Longitudinal analysis of household survey data. METHODS: A total of 6234 sample persons observed in the study of Assets and Health Dynamics Among the Oldest Old (AHEAD) 1995 were followed in 1998, 2000, and 2002 or until death or sample attrition. Effects of changes in self-reported vision and other factors were assessed by means of ordinary least-squares and logistic regression with panel data methods. Main outcome measures were limitations of instrumental activities of daily living (IADLs), activities of daily living (ADLs), and other, cognition, depressive symptoms, and living arrangements. RESULTS: A decline from excellent/good vision to fair/poor near and distance vision had statistically significant effects on several IADL limitations, and some ADL and other limitations. Largest effects were for driving (OR for no limitation: 0.55, P = .003), managing money (OR: 0.61, P < .001), and preparing hot meals (OR: 0.61, P < .001). Onset of fair-poor near vision increased the likelihood of onset of at least one IADL (OR for no limitation: 0.71, P < .01) and ADL (OR: 0.74, P = .003) limitation. Onset of legal blindness resulted in a 78% increase in the likelihood of an IADL limitation (OR for no limitation: 0.22, P < .001). Effects of vision declines on cognition and depressive symptoms were statistically significant but small. Decline in vision increased the probability of nursing home residence. CONCLUSIONS: Visual impairment has major impacts on functional status. Preventing vision loss is likely to appreciably improve the functioning of elderly persons.

Activities of Daily Living↗
PubMed2005

Longitudinal analysis of the relationship between regular eye examinations and changes in visual and functional status.

OBJECTIVES: To determine whether regular eye examinations are associated with a greater or lesser rate of loss of ability to read newsprint, onset of blindness or low vision, or onset of limitations in instrumental activities of daily living (IADLs) and activities of daily living (ADLs). DESIGN: A sample of 14,215 Medicare beneficiaries observed between 1994 and 1999 linked to the 1994 and 1999 National Long-Term Care Surveys (NLTCS). Effects of annual examinations were assessed using instrumental variables. SETTING: The Medicare-linked NLTCS is representative of U.S. elderly persons from 1994 to 1999. PARTICIPANTS: Longitudinal observational study of persons aged 65 and older. MEASUREMENTS: Change in self-reported and provider-reported vision and change in functional limitations associated with vision related to the number of years with eye examinations and other factors. RESULTS: Persons with more-regular eye examinations between 1994 and 1998 were less likely to have experienced a decline in vision or in functional status between 1994 and 1999. On average, an additional year with an eye examination was associated with a decrease in the probability of becoming unable to read newsprint of 0.12 (P=.03), a lower probability of onset of low vision or blindness of 0.009 (P=.06), and a decrease in the probability that the number of functional limitations increased of 0.13 (P=.002) for IADLs and 0.05 (P=.003) for ADLs. CONCLUSION: Elderly persons who have regular eye examinations experience less decline in vision and functional status.

Activities of Daily Living↗
PubMed2005

The role of price, sociodemographic factors, and health in the demand for bariatric surgery.

OBJECTIVES: To estimate the effect of price, sociodemographic factors, and health on the demand for bariatric surgery among eligible individuals with private health insurance, in order to enable policy makers and insurers to make more informed decisions concerning access to care for bariatric surgery. STUDY DESIGN: We conducted an Internet-based contingent valuation survey of 1802 obese persons eligible for bariatric surgery but who had not undergone the procedure. METHODS: We used multivariate regression analysis to separately estimate the likelihood of having gastric bypass and gastric banding surgery at different out-of-pocket costs. We combined the results with estimates of the privately insured bariatric surgery-eligible population from the National Health and Nutrition Examination Survey, 1999-2002, to estimate aggregate demand. RESULTS: Out-of-pocket cost was negatively and highly significantly related to the self-reported likelihood of having surgery. Persons with higher incomes and younger persons also reported a significantly higher likelihood of surgery. No effect was found for body mass index or for most comorbidities. We estimate that about 150 000 bariatric operations per year would be demanded by those with private health insurance at an out-of-pocket cost of USD 25 000. At USD 5000, we estimate a demand of 250 000 bariatric operations per year. CONCLUSIONS: Price is significantly and negatively related to the demand for bariatric surgery. At an out-of-pocket cost of USD 5000, about 2.2% of the bariatric surgery-eligible population would strongly consider surgery.

Adolescent↗
PubMed2005

A cost-benefit simulation model of coverage for bariatric surgery among full-time employees.

OBJECTIVE: To use a simulation model to estimate the costs and benefits of bariatric surgery among full-time employees. STUDY DESIGN: Multivariate regression analysis of nationally representative survey data sets to estimate the costs of obesity and a simulation model of the number of years until breakeven under alternate assumptions about the costs and benefits of bariatric surgery. METHODS: We used a 2-part model to estimate medical costs of obesity based on the 2000-2001 Medical Expenditure Panel Survey. We estimated work loss with a negative binomial regression based on the 2002 National Health Interview Survey. Using these results, we simulated the expected number of years required for a bariatric surgery procedure to become cost saving. RESULTS: Nine percent of the full-time US workforce, or 29% of the obese workforce, is eligible for bariatric surgery. Obese workers eligible for bariatric surgery have 5.1 (P < .01) additional days of work loss and USD 2230 (in 2004 dollars) (P < .01) higher annual medical costs than persons of normal weight. CONCLUSION: Although the cost implications of bariatric surgery among full-time employees depend on many factors, the simulations reveal that 5 or more years of follow-up are most likely required for these operations to become cost saving unless the employee bears a significant fraction of the total costs of the surgery.

Adolescent↗
PubMed2004

Monitoring visual status: why patients do or do not comply with practice guidelines.

OBJECTIVE: To determine factors affecting compliance with guidelines for annual eye examinations for persons diagnosed with diabetes mellitus (DM) or age-related macular degeneration (ARMD). DATA SOURCES/STUDY SETTING: Nationally representative, longitudinal sample of individuals 65+ drawn from the National Long-Term Care Survey (NLTCS) with linked Medicare claims records from 1991 to 1999. STUDY DESIGN: Medicare beneficiaries were followed from 1991 to 1999, unless mortality intervened. All claims data were analyzed for presence of ICD-9 codes indicating diagnosis of DM or ARMD and the performance of eye exams. The dependent variable was a binary indicator for whether a person had an eye exam or not during a 15-month period. Independent variables for demographics, living conditions, supplemental insurance, income, and other factors affecting the marginal cost and benefit of an eye exam were assessed to determine reasons for noncompliance. DATA COLLECTION/EXTRACTION METHODS: Panel data were created from claims files, 1991-1999, merged with data from the NLTCS. PRINCIPAL FINDINGS: The probability of having an exam reflected perceived benefits, which vary by patient characteristics (e.g., education, no dementia), and factors associated with the ease of visit. African Americans were much less likely to be examined than were whites. CONCLUSIONS: Having an exam reflects multiple factors. However, much of the variation in the probability of an exam remained unexplained as were reasons for the racial differences in use.

Aged↗
PubMed2003

Estimates of incidence rates with longitudinal claims data.

OBJECTIVE: To estimate incidence rates of the 3 major chronic eye diseases--diabetic retinopathy (DR), glaucoma, and age-related macular degeneration (ARMD)--by using longitudinal claims data from Medicare. METHODS: Longitudinal cases were ascertained by using a national probability sample of Medicare beneficiaries aged 65 years and older in 1991 who initially had none of the eye diseases documented. After adjusting for death and enrollment in a health maintenance organization, claims filed by optometrists or ophthalmologists with an International Classification of Diseases, Ninth Revision, Clinical Modification code for all forms of DR, glaucoma, and ARMD were used to indicate diagnosis. RESULTS: Annual incidence rates for the 3 conditions after the first year of observation ranged from 14.3% to 17.7% (higher earlier) across an 8-year longitudinal follow-up. Incidence rates among those with diabetes mellitus for any form of DR varied between 3.8% and 6.5%, while those for glaucoma varied between 4.6% and 7.8% and those for ARMD varied between 7.5% and 9.3%. CONCLUSIONS: Longitudinal claims data after the first year provide relatively stable estimates of incidence rates on an annual basis. These estimates are comparable with those of the few population-based studies available.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed2003

Longitudinal prevalence of major eye diseases.

OBJECTIVE: To describe the prevalence across time of 3 chronic eye diseases among a representative cohort of elderly subjects. STUDY DESIGN: Longitudinal observation of Medicare claims. Population A random sample of Medicare beneficiaries 65 years and older, nationally representative at baseline. MAIN OUTCOME MEASURES: Diagnosis of diabetic retinopathy, glaucoma, and age-related macular degeneration. METHODS: Beneficiaries were followed from 1991 to 1999 unless mortality or enrollment in a health maintenance organization for 6 or more months in a year intervened. Claims data were analyzed for the presence of codes from the International Classification of Diseases, Ninth Revision, Clinical Modification, indicating 1 of the 3 conditions. Transitions between severity stages were also evaluated. RESULTS: Of 20 325 beneficiaries in 1991, 10 476 were available for analysis in 1999. The prevalence of diabetes mellitus increased from 14.5% in 1991 to 25.6% by 1999, with diabetic retinopathy among persons with diabetes mellitus increasing from 6.9% to 17.4%. Primary open-angle glaucoma increased from 4.6% to 13.8%. The percentage of glaucoma suspects increased from 1.5% to 6.5%, as did the percentage of narrow-angle glaucoma (0.7%-2.7%). The prevalence of age-related macular degeneration increased from 5.0% to 27.1%. Overall, the proportion of subjects with at least 1 of these 3 diseases increased from 13.4% to 45.4%. CONCLUSIONS: The clinical diagnosis of major chronic eye diseases associated with aging increased dramatically in a longitudinal sample. At the end of 9 years, nearly half of the surviving Medicare beneficiaries had at least 1 of these diseases.

Aged↗
PubMed2003

Longitudinal rates of annual eye examinations of persons with diabetes and chronic eye diseases.

OBJECTIVE: To assess the rate of annual eye examinations over time among older Americans with diabetes and chronic eye diseases. DESIGN: Longitudinal analysis of Medicare claims data. PARTICIPANTS: Random sample of Medicare beneficiaries aged 65 years or older. METHODS: Beneficiaries were followed between 1991 and 1999, unless mortality or enrollment in a health maintenance organization for > 6 months in a given 12-month period intervened. All claims data (both physician and facility) during this time were analyzed for the presence of International Classification of Diseases 9 codes consistent with 1 of the 3 study conditions and the performance of eye examinations. MAIN OUTCOME MEASURES: Claims submitted by optometrists, ophthalmologists, or other providers of eye care for subjects with diabetes, glaucoma, or age-related macular degeneration (ARMD). Rates were calculated on the basis of a 15-month time window for annual examinations rather than for 12 months to allow for less than full compliance with the guidelines for various reasons (e.g., bad weather). RESULTS: Among those with diabetes in this population, 50% to 60% had annual eye examinations in a 15-month period. Of those followed for at least 75 months after diagnosis, about three quarters had one or more 15-month gaps between visits. For subjects diagnosed with glaucoma, most visit rates were in the 70% to 90% range per 15-month period. The percentage of subjects with at least one 15-month period with no visits was considerably lower than for diabetes. The patterns for those with ARMD were in between those for diabetes and glaucoma. Over a nine-year period, only slightly over half of persons with at least one of the study conditions complied with practice guidelines. CONCLUSIONS: Annual eye examinations for persons diagnosed with diabetes, glaucoma, and ARMD are important for detecting potentially treatable vision loss among those already diagnosed with these conditions. Currently, actual rates of eye examinations for persons diagnosed with the study conditions fall far short of recommended rates. As such, approaches to enhancing longitudinal follow-up of those already in the eye care system are needed.

Aged↗
PubMedDate not supplied

Changing perceptions of the childhood obesity epidemic.

OBJECTIVES: To examine changes in public attitudes about childhood obesity and support for prevention. METHODS: RTI surveyed US households (N = 1047 and N = 1139) about perceived severity, causes, and support for specific obesity interventions. Logistic regressions examined differences in obesity attitudes and support for prevention. RESULTS: Perceived health threat of childhood obesity increased between the 2 surveys. Support increased for interventions such as regulation of restaurant portions and fast food advertising. Logistic regressions revealed differences among sociodemographic groups. CONCLUSIONS: Public support for childhood obesity prevention is increasing. Policy makers can use these findings to develop appropriate prevention strategies.

Adolescent↗