Evaluation of Non-Response Bias in a Cohort Study of World Trade Center Terrorist Attack Survivors

Details

• Journal Article:
  BMC Res Notes
• Personal Author:
  Yu, Shengchao ; Brackbill, Robert M. ; Stellman, Steven D. ; Ghuman, Sharon ; Farfel, Mark R.
• Description:
  Background
  
  Few longitudinal studies of disaster cohorts have assessed both non-response bias in prevalence estimates of health outcomes and in the estimates of associations between health outcomes and disaster exposures. We examined the factors associated with non-response and the possible non-response bias in prevalence estimates and association estimates in a longitudinal study of World Trade Center (WTC) terrorist attack survivors.
  
  Methods
  
  In 2003–04, 71,434 enrollees completed the WTC Health Registry wave 1 health survey. This study is limited to 67,670 adults who were eligible for both wave 2 and wave 3 surveys in 2006–07 and 2011–12. We first compared the characteristics between wave 3 participants (wave 3 drop-ins and three-wave participants) and non-participants (wave 3 drop-outs and wave 1 only participants). We then examined potential non-response bias in prevalence estimates and in exposure-outcome association estimates by comparing one-time non-participants (wave 3 drop-ins and drop-outs) at the two follow-up surveys with three-wave participants.
  
  Results
  
  Compared to wave 3 participants, non-participants were younger, more likely to be male, non-White, non-self enrolled, non-rescue or recovery worker, have lower household income, and less than post-graduate education. Enrollees’ wave 1 health status had little association with their wave 3 participation. None of the disaster exposure measures measured at wave 1 was associated with wave 3 non-participation. Wave 3 drop-outs and drop-ins (those who participated in only one of the two follow-up surveys) reported somewhat poorer health outcomes than the three-wave participants. For example, compared to three-wave participants, wave 3 drop-outs had a 1.4 times higher odds of reporting poor or fair health at wave 2 (95% CI 1.3-1.4). However, the associations between disaster exposures and health outcomes were not different significantly among wave 3 drop-outs/drop-ins as compared to three-wave participants.
  
  Conclusion
  
  Our results show that, despite a downward bias in prevalence estimates of health outcomes, attrition from the WTC Health Registry follow-up studies does not lead to serious bias in associations between 9/11 disaster exposures and key health outcomes. These findings provide insight into the impact of non-response on associations between disaster exposures and health outcomes reported in longitudinal studies.
  
  
• Subjects:
  Emergency Responders Health Status Health Surveys Inhalation Exposure Longitudinal Studies Respiratory Hypersensitivity September 11 Terrorist Attacks Stress Disorders, Post-Traumatic Surveys And Questionnaires Survivors
• Keywords:
  Author Keywords: Non-response; Bias; Disaster; 9/11 Exposure; Probable Posttraumatic Stress Disorder; Lower Respiratory Symptoms; Drop-ins; Drop-outs Emergency-response; Health-programs; Group-behavior; Group-dynamics; Medical-treatment; Health-care; Health-surveys; Health-services; Qualitative-analysis; Humans; Psychological-responses; Surveillance-programs; Behavior; Decision-making; Attitude; Health-hazards; Hazardous-materials; Long-term-study; Respiratory-system-disorders; Exposure-assessment; Medical-monitoring; Epidemiology; Statistical-analysis; Statistical-quality-control;
• Source:
  BMC Res Notes. 8.
• Pubmed ID:
  25889176
• Pubmed Central ID:
  PMC4409729
• Document Type:
  Text
• Funding:
  1U50OH009739/OH/NIOSH CDC HHS/United States ; 2U50OH009739/OH/NIOSH CDC HHS/United States ; U50/ATU272750/PHS HHS/United States
• Genre:
  Journal Article
• Place as Subject:
  New York ; OSHA Region 2
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  11 pdf pages
• Volume:
  8
• Issue:
  1
• NIOSHTIC Number:
  nn:20046137 ; nn:20046173
• Federal Fiscal Year:
  2015
• Performing Organization:
  New York City Health/Mental Hygiene
• Peer Reviewed:
  True
• Collection(s):
  CDC Public Access National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a05f19e0da91c443841c245361709241590a18e5da00505c18d342a15e986aa99f60028cf7388fcc96efa78622dbfad0d85fb70753bcd24a73f0dec4385f10f2
• Download URL:
  https://stacks.cdc.gov/view/cdc/32361/cdc_32361_DS1.pdf
• File Type:
  [PDF - 1.00 MB ]