Biomedical subjects

Paul D Allison

Publications and source records attributed to Paul D Allison.

3 recordsLinked to original sources

PubMed2004

Estimation of cumulative odds ratios.

PURPOSE: Standard estimation of ordered odds ratios requires the constraint that the etiologic effects of exposure are homogenous across thresholds of the ordered response. We present a method to relax this often-unrealistic constraint. METHODS: The kernel of the proposed method is the expansion of observed data into "person-thresholds." Using standard statistical software, for each subject we create a separate record for each response threshold and then apply binary logistic regression to estimate generalized cumulative odds ratios for one or more exposures. RESULTS: Two examples demonstrate that the proposed method provides increased flexibility in assessing the etiologic effects of exposures. A Monte Carlo simulation study supports the proposed approach by suggesting the estimated cumulative odds ratios are unbiased with proper confidence interval coverage attained by use of generalized estimating equations. CONCLUSION: The proposed method provides simple estimates of ordered odds ratios that allow the etiologic effects of exposure to vary across levels of the ordered response.

Diabetic Retinopathy↗

PubMed2003

Missing data techniques for structural equation modeling.

As with other statistical methods, missing data often create major problems for the estimation of structural equation models (SEMs). Conventional methods such as listwise or pairwise deletion generally do a poor job of using all the available information. However, structural equation modelers are fortunate that many programs for estimating SEMs now have maximum likelihood methods for handling missing data in an optimal fashion. In addition to maximum likelihood, this article also discusses multiple imputation. This method has statistical properties that are almost as good as those for maximum likelihood and can be applied to a much wider array of models and estimation methods.

Adult↗

PubMed2002

Factors associated with distress in urban residential fire survivors.

PURPOSE: To identify factors associated with recovery in a sample of urban residential fire survivors. DESIGN AND METHODS: 440 survivors, of residential fires were interviewed at approximately 3, 6, and 13 months after the fire to measure psychological distress. A set of factors was identified that correlated with survivors' ability to recover from the fire event. Potential predictors of increased distress were identified. Hypotheses were that participants who were lower in socioeconomic status, who were minority members, who had less social support, who engaged in attributional thinking, and had greater concurrent life stresses would have greater psychological distress in response to a residential fire and would be less able to recover from the fire event. FINDINGS: Distress after fire was high at 3 months and decreased for the majority of participants, although one-third of survivors had higher distress at 13 months than at 3 months. Loss of control and attributional variables had the strongest influence on psychological distress over time. CONCLUSIONS: The findings are consistent with stress-response tendencies expected after a stressful event. A set of predictor variables was identified to help clinicians target survivors at high risk for psychological distress after a residential fire.

Adolescent↗