A Comparison of Cluster-Specific and Population-Averaged Approaches for Analyzing Correlated Binary DataJ. M. Neuhaus, J. D. Kalbfleisch, W. W. Hauck, A Comparison of Cluster-Specific and Population-Averaged Approaches for Analyzing Correlated Binary Data, International Statistical Review / Revue Internationale de Statistique, Vol. 59, No. 1 (Apr., 1991), pp. 25-35
A Randomized, Controlled Trial of a Home Environmental InterventionPURPOSE OF STUDY: The authors determined short-term effects of a home environmental intervention on self-efficacy and upset in caregivers and daily function of dementia patients. They also determined if treatment effect varied by caregiver gender, race, and relationship to patient. DESIGN AND METHODS: Families (N = 171) of dementia patients were randomized to intervention or usual care control group. The intervention involved 5 90-min home visits by occupational therapists who provided education and physical and social environmental modifications. RESULTS: Compared with controls, intervention caregivers reported fewer declines in patients' instrumental activities of daily living (p = .030) and less decline in self-care and fewer behavior problems in patients at 3 months post-test. Also, intervention spouses reported reduced upset (p = .049), women reported enhanced self-efficacy in managing behaviors (p = .038), and women (p = .049) and minorities (p = .037) reported enhanced self-efficacy in managing functional dependency. IMPLICATIONS: The environmental program appears to have a modest effect on dementia patients' IADL dependence. Also, among certain subgroups of caregivers the program improves self-efficacy and reduces upset in specific areas of caregiving.
Effect of multicomponent interventions on caregiver burden and depression: The REACH multisite initiative at 6-month follow-up.Meta-analysis was used to examine pooled parameter estimates of 9 active compared with 6 control conditions of the Resources for Enhancing Alzheimer's Caregiver Health (REACH) project at 6 months on caregiver burden and depressive symptoms. Associations of caregiver characteristics and outcomes were examined. For burden, active interventions were superior to control conditions (p = .022). Also, active interventions were superior to control conditions for women versus men and for caregivers with lower education versus those with higher education. For depressive symptoms, a statistically significant association of group assignment was found for Miami's family therapy and computer technology intervention (p = .034). Also, active interventions were superior to control conditions for Hispanics, nonspouses, and caregivers with lower education. Results suggest interventions should be multicomponent and tailored.
A Randomized Trial of a Multicomponent Home Intervention to Reduce Functional Difficulties in Older AdultsLaura N. Gitlin, Laraine Winter, Marie P. Dennis et al.|Journal of the American Geriatrics Society|2006 OBJECTIVES: To test the efficacy of a multicomponent intervention to reduce functional difficulties, fear of falling, and home hazards and enhance self-efficacy and adaptive coping in older adults with chronic conditions. DESIGN: A prospective, two-group, randomized trial. Participants were randomized to a treatment group or no-treatment group. SETTING: Urban community-living older people. PARTICIPANTS: Three hundred nineteen community-living adults aged 70 and older who reported difficulty with one or more activities of daily living. INTERVENTION: Occupational and physical therapy sessions involving home modifications and training in their use; instruction in strategies of problem-solving, energy conservation, safe performance, and fall recovery techniques; and balance and muscle strength training. MEASUREMENTS: Outcome measures included self-rated functional difficulties with ambulation, instrumental activities of daily living, activities of daily living, fear of falling, confidence performing daily tasks, and use of adaptive strategies. Observations of home hazards were also conducted. RESULTS: At 6 months, intervention participants had less difficulty than controls with instrumental activities of daily living (P=.04, 95% confidence interval (CI)=-0.28-0.00) and activities of daily living (P=.03, 95% CI=-0.24 to -0.01), with largest reductions in bathing (P=.02, 95% CI=-0.52 to -0.06) and toileting (P=.049, 95% CI=-0.35-0.00). They also had greater self-efficacy (P=.03, 95% CI=0.02-0.27), less fear of falling (P=.001, 95% CI=0.26-0.96), fewer home hazards (P=.05, 95% CI=-3.06-0.00), and greater use of adaptive strategies (P=.009, 95% CI=0.03-0.22). Benefits were sustained at 12 months for most outcomes. CONCLUSION: A multicomponent intervention targeting modifiable environmental and behavioral factors results in life quality improvements in community-dwelling older people who had functional difficulties, with most benefits retained over a year.
Wald's Test as Applied to Hypotheses in Logit AnalysisWalter W. Hauck, Allan Donner|Journal of the American Statistical Association|1977 Abstract For tests of a single parameter in the binomial logit model, Wald's test is shown to behave in an aberrant manner. In particular, the test statistic decreases to zero as the distance between the parameter estimate and null value increases, and the power of the test, based on its large-sample distribution, decreases to the significance level for alternatives sufficiently far from the null value.