Selective attrition and bias in a longitudinal health survey among survivors of a disaster

BACKGROUND: Little is known about the response mechanisms among survivors of disasters. We studied the selective attrition and possible bias in a longitudinal study among survivors of a fireworks disaster. METHODS: Survivors completed a questionnaire three weeks (wave 1), 18 months (wave 2) and four years post-disaster (wave 3). Demographic characteristics, disaster-related factors and health problems at wave 1 were compared between respondents and non-respondents at the follow-up surveys. Possible bias as a result of selective response was examined by comparing prevalence estimates resulting from multiple imputation and from complete case analysis. Analysis were stratified according to ethnic background (native Dutch and immigrant survivors). RESULTS: Among both native Dutch and immigrant survivors, female survivors and survivors in the age categories 25–44 and 45–64 years old were more likely to respond to the follow-up surveys. In general, disasters exposure did not differ between respondents and non-respondents at follow-up. Response at follow-up differed between native Dutch and non-western immigrant survivors. For example, native Dutch who responded only to wave 1 reported more depressive feelings at wave 1 (59.7%; 95% CI 51.2–68.2) than Dutch survivors who responded to all three waves (45.4%; 95% CI 41.6–49.2, p < 0.05). Immigrants who responded only to wave 1 had fewer health problems three weeks post-disaster such as depressive feelings (M = 69.3%; 95% CI 60.9–77.6) and intrusions and avoidance reactions (82.7%; 95% CI 75.8–89.5) than immigrants who responded to all three waves (respectively 89.9%; 95% CI 83.4–96.9 and 96.3%; 95% CI 92.3–100, p < .01). Among Dutch survivors, the imputed prevalence estimates of wave 3 health problems tended to be higher than the complete case estimates. The imputed prevalence estimates of wave 3 health problems among immigrants were either unaffected or somewhat lower than the complete case estimates. CONCLUSION: Our results indicate that despite selective response, the complete case prevalence estimates were only somewhat biased. Future studies, both among survivors of disasters and among the general population, should not only examine selective response, but should also investigate whether selective response has biased the complete case prevalence estimates of health problems by using statistical techniques such as multiple imputation

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Hurricane Katrina: Maternal Depression Trajectories and Child Outcomes

BACKGROUND: The authors examined depression trajectories over two years among mothers exposed to Hurricane Katrina. Risk and protective factors for depression trajectories, as well as associations with child outcomes were analyzed. METHOD: This study included 283 mothers (age at time 1, M = 39.20 years, SD = 7.21; 62% African American). Mothers were assessed at four time points over two years following Hurricane Katrina. Mothers reported posttraumatic stress symptoms, hurricane exposure, traumatic life events, and social support at time 1. Depressive symptoms were modeled at times 2, 3, and 4. Youth reported their distress symptoms (posttraumatic stress, depression, and anxiety) at time 4. RESULTS: Latent class growth analyses identified three maternal depression trajectories among mothers exposed to Hurricane Katrina: low (61%), resilient (29%), and chronic (10%). Social support was identified as a protective factor among mothers. CONCLUSIONS: Three main trajectories of maternal depression following Hurricane Katrina were identified. Social support was protective for mothers. Identified trajectories were not associated with children’s distress outcomes. These results have implications for disaster responses, screening efforts, and interventions targeted towards families. Future studies warrant the investigation of additional risk and protective factors that can affect maternal and child outcomes