Biomedical subjects
Publications and source records attributed to David F Williamson.
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OBJECTIVE: The aim of this study was to examine the relationships between intention to lose weight, actual weight loss, and all-cause mortality among overweight individuals with diabetes. RESEARCH DESIGN AND METHODS: We performed a prospective analysis among 1,401 overweight diabetic adults aged > or =35 years sampled in the National Health Interview Survey. The previous year intention to lose weight and weight change were assessed by self-report. Nine-year mortality rates were examined according to intent to lose weight and weight loss, which were adjusted for age, sex, education, ethnicity, smoking, initial body weight, and diabetes complications. RESULTS: Individuals trying to lose weight had a 23% lower mortality rate (hazard rate ratio [HRR] 0.77, 95% CI 0.61-0.99) than those who reported not trying to lose weight. This association was as strong for those who failed to lose weight (0.72, 0.55-0.96) as for those who succeeded in losing weight (0.83, 0.63-1.08). Trying to lose weight was beneficial for overweight (BMI 25-30 kg/m2) individuals (0.62, 0.46-0.83) but not for obese (BMI>30) individuals (1.17, 0.72-1.92). Overall weight loss, without regard to intent, was associated with an increase of 22% (1.22, 0.99-1.50) in the mortality rate. This increase was largely explained by unintentional weight loss, which was associated with a 58% (1.58, 1.08-2.31) higher mortality rate. CONCLUSIONS: Overweight diabetic adults trying to lose weight have a reduced risk of all-cause mortality, independent of whether they lose weight. Actual weight loss is associated with increased mortality only if the weight loss is unintentional.
OBJECTIVE: To examine the association between the organizational model and diabetes processes of care. RESEARCH DESIGN AND METHODS: We used data from the Translating Research into Action for Diabetes (TRIAD), a multicenter study of diabetes care in managed care, including 8354 patients with diabetes. We identified five model types: for-profit group/network, for-profit independent practice association (IPA), nonprofit group/network, nonprofit IPA, and nonprofit group/staff. Process measures included retinal, renal, foot, lipid, and HbA(1c) testing; aspirin recommendations; influenza vaccination; and a sum of these seven processes of care over 1 year. Hierarchical regression models were constructed for each process measure and accounted for clustering at the health plan and provider group levels and adjusted for participant age, sex, race, ethnicity, diabetes treatment and duration, education, income, health status, and survey language. RESULTS: Participant membership in the model types ranged from 9% in nonprofit IPA models to 38% in nonprofit group/staff models. Over 75% of participants received most of the processes of care, regardless of model type. However, among for-profit plans, group/network models provided on average more processes of care than IPA models (5.5 vs. 4.7, P < 0.0001), and group/network models generally increased the probability of receiving a process by >or=10 percentage points. Among nonprofit plans, no effect of model type was found. CONCLUSIONS: Among for-profit plans, group/network models provided better diabetes processes of care than IPA models. Although reasons are speculative, this may be due to the clinical infrastructure available in group models that is not available in IPA models.
OBJECTIVE: To examine the effect of referral management on diabetes care. STUDY DESIGN: Cross-sectional analysis. PATIENTS AND METHODS: Translating Research Into Action for Diabetes (TRIAD) is a multicenter study of managed care enrollees with diabetes. Prospective referral management was defined as "gatekeeping" and mandatory preauthorization from a utilization management office, and retrospective referral management as referral profiling and appropriateness reviews. Outcomes included dilated eye exam; self-reported visit to specialists; and perception of difficulty in getting referrals. Hierarchical models adjusted for clustering and patient age, gender, race, ethnicity, type and duration of diabetes treatment, education, income, health status, and comorbidity. RESULTS: Referral management was commonly used by health plans (55%) and provider groups (52%). In adjusted analyses, we found no association between any referral management strategies and any of the outcome measures. CONCLUSIONS: Referral management does not appear to have an impact on referrals or perception of referrals related to diabetes care.
CONTEXT: Although diabetes mellitus is one of the most prevalent and costly chronic diseases in the United States, no estimates have been published of individuals' average lifetime risk of developing diabetes. OBJECTIVE: To estimate age-, sex-, and race/ethnicity-specific lifetime risk of diabetes in the cohort born in 2000 in the United States. DESIGN, SETTING, AND PARTICIPANTS: Data from the National Health Interview Survey (1984-2000) were used to estimate age-, sex-, and race/ethnicity-specific prevalence and incidence in 2000. US Census Bureau data and data from a previous study of diabetes as a cause of death were used to estimate age-, sex-, and race/ethnicity-specific mortality rates for diabetic and nondiabetic populations. MAIN OUTCOME MEASURES: Residual (remaining) lifetime risk of diabetes (from birth to 80 years in 1-year intervals), duration with diabetes, and life-years and quality-adjusted life-years lost from diabetes. RESULTS: The estimated lifetime risk of developing diabetes for individuals born in 2000 is 32.8% for males and 38.5% for females. Females have higher residual lifetime risks at all ages. The highest estimated lifetime risk for diabetes is among Hispanics (males, 45.4% and females, 52.5%). Individuals diagnosed as having diabetes have large reductions in life expectancy. For example, we estimate that if an individual is diagnosed at age 40 years, men will lose 11.6 life-years and 18.6 quality-adjusted life-years and women will lose 14.3 life-years and 22.0 quality-adjusted life-years. CONCLUSIONS: For individuals born in the United States in 2000, the lifetime probability of being diagnosed with diabetes mellitus is substantial. Primary prevention of diabetes and its complications are important public health priorities.
BACKGROUND: Walking is associated with reduced diabetes incidence, but few studies have examined whether it reduces mortality among those who already have diabetes. OBJECTIVE: To estimate the association between walking and the risk for all-cause and cardiovascular disease (CVD) mortality among persons with diabetes. DESIGN: Prospective cohort study of a representative sample of the US population. SETTING: Interviewer-administered survey in the general community. PARTICIPANTS: We sampled 2896 adults 18 years and older with diabetes as part of the 1990 and 1991 National Health Interview Survey. MAIN OUTCOME MEASURE: All-cause and CVD mortality for 8 years. RESULTS: Compared with inactive individuals, those who walked at least 2 h/wk had a 39% lower all-cause mortality rate (hazard rate ratio [HRR], 0.61; 95% confidence interval [CI], 0.48-0.78; 2.8% vs 4.4% per year) and a 34% lower CVD mortality rate (HRR, 0.66; 95% CI, 0.45-0.96; 1.4% vs 2.1% per year). We controlled for sex, age, race, body mass index (calculated as weight in kilograms divided by the square of height in meters), smoking, and comorbid conditions. The mortality rates were lowest for persons who walked 3 to 4 h/wk (all-cause mortality HRR, 0.46; 95% CI, 0.29-0.71; CVD mortality HRR, 0.47; 95% CI, 0.24-0.91) and for those who reported that their walking involved moderate increases in heart and breathing rates (all-cause mortality HRR, 0.57; 95% CI, 0.41-0.80; CVD mortality HRR, 0.69; 95% CI, 0.43-1.09). The protective association of physical activity was observed for persons of varying sex, age, race, body mass index, diabetes duration, comorbid conditions, and physical limitations. CONCLUSIONS: Walking was associated with lower mortality across a diverse spectrum of adults with diabetes. One death per year may be preventable for every 61 people who could be persuaded to walk at least 2 h/wk.
BACKGROUND: Although weight loss improves risk factors for cardiovascular and metabolic disease, it is unclear whether intentional weight loss reduces mortality rates. OBJECTIVE: To examine the relationships among intention to lose weight, weight loss, and all-cause mortality. DESIGN: Prospective cohort study using a probability sample of the U.S. population. SETTING: Interviewer-administered survey. PARTICIPANTS: 6391 overweight and obese persons (body mass index > or = 25 kg/m2) who were at least 35 years of age. MEASUREMENTS: Intention to lose weight and weight change during the past year were assessed by self-report in 1989. Vital status was followed for 9 years. Hazard rate ratios (HRRs) were adjusted for age, sex, ethnicity, education, smoking, health status, health care utilization, and initial body mass index. RESULTS: Compared with persons not trying to lose weight and reporting no weight change, those reporting intentional weight loss had a 24% lower mortality rate (HRR, 0.76 [95% CI, 0.60 to 0.97]) and those with unintentional weight loss had a 31% higher mortality rate (HRR, 1.31 [CI, 1.01 to 1.70]). However, mortality rates were lower in persons who reported trying to lose weight than those in not trying to lose weight, independent of actual weight change. Compared with persons not trying to lose weight and reporting no weight change, persons trying to lose weight had the following HRRs: no weight change, 0.80 (CI, 0.65 to 0.99); gained weight, 0.94 (CI, 0.65 to 1.37); and lost weight, 0.76 (CI, 0.60 to 0.97). CONCLUSIONS: Attempted weight loss is associated with lower all-cause mortality, independent of weight change. Self-reported intentional weight loss is associated with lower mortality rates, and weight loss is associated with higher mortality rates only if it is unintentional.
OBJECTIVE: To describe the costs of the Diabetes Prevention Program (DPP) interventions to prevent or delay type 2 diabetes. RESEARCH DESIGN AND METHODS: We describe the direct medical costs, direct nonmedical costs, and indirect costs of the placebo, metformin, and intensive lifestyle interventions over the 3-year study period of the DPP. Resource use and cost are summarized from the perspective of a large health system and society. Research costs are excluded. RESULTS: The direct medical cost of laboratory tests to identify one subject with impaired glucose tolerance (IGT) was $139. Over 3 years, the direct medical costs of the interventions were $79 per participant in the placebo group, $2,542 in the metformin group, and $2,780 in the lifestyle group. The direct medical costs of care outside the DPP were $272 less per participant in the metformin group and $432 less in the lifestyle group compared with the placebo group. Direct nonmedical costs were $9 less per participant in the metformin group and $1,445 greater in the lifestyle group compared with the placebo group. Indirect costs were $230 greater per participant in the metformin group and $174 less in the lifestyle group compared with the placebo group. From the perspective of a health system, the cost of the metformin intervention relative to the placebo intervention was $2,191 per participant and the cost of the lifestyle intervention was $2,269 per participant over 3 years. From the perspective of society, the cost of the metformin intervention relative to the placebo intervention was $2,412 per participant and the cost of the lifestyle intervention was $3,540 per participant over 3 years. CONCLUSIONS: The metformin and lifestyle interventions are associated with modest incremental costs compared with the placebo intervention. The evaluation of costs relative to health benefits will determine the value of these interventions to health systems and society.
OBJECTIVE: Few studies have investigated risk factors that predispose males to be involved in teen pregnancies. To provide new information on such factors, we examined the relationships of eight common adverse childhood experiences to a male's risk of impregnating a teenager. METHODS: We conducted a retrospective cohort study using questionnaire responses from 7399 men who visited a primary care clinic of a large health maintenance organization in California. Data included age of the youngest female ever impregnated; the man's own age at the time; his history of childhood emotional, physical, or sexual abuse; having a battered mother; parental separation or divorce; and having household members who were substance abusers, mentally ill, or criminals. Odds ratios (ORs) for the risk of involvement in a teen pregnancy were adjusted for age, race, and education. RESULTS: At least one adverse childhood experience was reported by 63% of participants, and 34% had at least two adverse childhood experiences; 19% of men had been involved in a teen pregnancy. Each adverse childhood experience was positively associated with impregnating a teenager, with ORs ranging from 1.2 (sexual abuse) to 1.8 (criminal in home). We found strong graded relationships (P <.001) between the number of adverse childhood experiences and the risk of involvement in a teen pregnancy for each of four birth cohorts during the last century. Compared with males with no adverse childhood experiences, a male with at least five adverse childhood experiences had an OR of 2.6 (95% confidence interval [CI] 2.0, 3.4) for impregnating a teenager. The magnitude of the ORs for the adverse childhood experiences was reduced 64-100% by adjustment for potential intermediate variables (age at first intercourse, number of sexual partners, having a sexually transmitted disease, and alcohol or drug abuse) that also exhibited a strong graded relationship to adverse childhood experiences. CONCLUSION: Adverse childhood experiences have an important relationship to male involvement in teen pregnancy. This relationship has persisted throughout four successive birth cohorts dating back to 1900-1929, suggesting that the effects of adverse childhood experiences transcend changing sexual mores and contraceptive methods. Efforts to prevent teen pregnancy will likely benefit from preventing adverse childhood experiences and their associated effects on male behaviors that might mediate the increased risk of teen pregnancy.
OBJECTIVE: The study examined how growing up with alcoholic parents and having adverse childhood experiences are related to the risk of alcoholism and depression in adulthood. METHODS: In this retrospective cohort study, 9,346 adults who visited a primary care clinic of a large health maintenance organization completed a survey about nine adverse childhood experiences: experiencing childhood emotional, physical, and sexual abuse; witnessing domestic violence; parental separation or divorce; and growing up with drug-abusing, mentally ill, suicidal, or criminal household members. The associations between parental alcohol abuse, the adverse experiences, and alcoholism and depression in adulthood were assessed by logistic regression analyses. RESULTS: The risk of having had all nine of the adverse childhood experiences was significantly greater among the 20 percent of respondents who reported parental alcohol abuse. The number of adverse experiences had a graded relationship to alcoholism and depression in adulthood, independent of parental alcohol abuse. The prevalence of alcoholism was higher among persons who reported parental alcohol abuse, no matter how many adverse experiences they reported. The association between parental alcohol abuse and depression was accounted for by the higher risk of having adverse childhood experiences in alcoholic families. CONCLUSIONS: Children in alcoholic households are more likely to have adverse experiences. The risk of alcoholism and depression in adulthood increases as the number of reported adverse experiences increases regardless of parental alcohol abuse. Depression among adult children of alcoholics appears to be largely, if not solely, due to the greater likelihood of having had adverse childhood experiences in a home with alcohol-abusing parents.
Intimate partner violence (IPV) damages a woman's physical and mental well-being, and indicates that her children are likely to experience abuse, neglect and other traumatic experiences. Adult HMO members completed a questionnaire about adverse childhood experiences (ACEs) including childhood abuse, neglect, and household dysfunction. We used their responses to retrospectively assess the relationship between witnessing intimate partner violence and experiencing any of the 9 ACEs and multiple ACEs (ACE score). Compared to persons who grew up with no domestic violence, the adjusted odds ratio for any individual ACE was approximately two to six times higher if IPV occurred (p < 0.05). There was a powerful graded increase in the prevalence of every category of ACE as the frequency of witnessing IPV increased. In addition, the total number of ACEs was increased dramatically for persons who had witnessed IPV during childhood. There was a positive graded risk for self-reported alcoholism, illicit drug use, i.v. drug use and depressed affect as the frequency of witnessing IPV increased. Identification of victims of IPV must include screening of their children for abuse, neglect and other types of adverse exposures, as well as recognition that substance abuse and depressed affect are likely consequences of witnessing IPV. Finally, this data strongly suggest that future studies, which focus on the effect of witnessing IPV on long-term health outcomes, may need to take into consideration the co-occurrence of multiple ACEs, which can also affect these outcomes.
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BACKGROUND: Several interventions can be applied to prevent complications of type 2 diabetes. This article examines the optimal allocation of resources across 4 interventions to treat patients newly diagnosed with type 2 diabetes. The interventions are intensive glycemic control, intensified hypertension control, cholesterol reduction, and smoking cessation. METHODS: A linear programming model was designed to select sets of interventions to maximize quality-adjusted life years (QALYs), subject to varied budget and equity constraints. RESULTS: For no additional cost, approximately 211,000 QALYs can be gained over the lifetimes of all persons newly diagnosed with diabetes by implementing interventions rather than standard care. With increased availability of funds, additional health benefits can be gained but with diminishing marginal returns. The impact of equity constraints is extensive compared to the solution with the same intervention costs and no equity constraint. Under the conditions modeled, intensified hypertension control and smoking cessation interventions were provided most often, and intensive glycemic control and cholesterol reduction interventions were provided less often. CONCLUSIONS: A resource allocation model identifies trade-offs involved when imposing budget and equity constraints on care for individuals with newly diagnosed diabetes.
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