Participant Blinding and Gastrointestinal Illness in a Randomized, Controlled Trial of an In-Home Drinking Water Intervention

Details

• Alternative Title:
  Emerg Infect Dis
• Personal Author:
  Colford, John M. ; Rees, Judy R. ; Wade, Timothy J. ; Khalakdina, Asheena ; Hilton, Joan F. ; Ergas, Isaac J. ; Burns, Susan ; Benker, Anne ; Ma, Catherine ; Bowen, Cliff ; Mills, Daniel C. ; Vugia, Duc J. ; Juranek, Dennis D. ; Levy, Deborah A.
• Description:
  We conducted a randomized, triple-blinded home drinking water intervention trial to determine if a large study could be undertaken while successfully blinding participants. Households were randomized 50:50 to use externally identical active or sham treatment devices. We measured the effectiveness of blinding of participants by using a published blinding index in which values >0.5 indicate successful blinding. The principal health outcome measured was "highly credible gastrointestinal illness" (HCGI). Participants (n=236) from 77 households were successfully blinded to their treatment assignment. At the end of the study, the blinding index was 0.64 (95% confidence interval 0.51-0.78). There were 103 episodes of HCGI during 10,790 person-days at risk in the sham group and 82 episodes during 11,380 person-days at risk in the active treatment group. The incidence rate ratio of disease (adjusted for the clustered sampling) was 1.32 (95% CI 0.75, 2.33) and the attributable risk was 0.24 (95% CI -0.33, 0.57). These data confirm that participants can be successfully blinded to treatment group assignment during a randomized trial of an in-home drinking water intervention.
• Subjects:
  Adolescent Adult Aged Child Double-Blind Method Drinking Feasibility Studies Female Gastrointestinal Diseases Humans Male Middle Aged Pilot Projects Quality Control Questionnaires Research Water Purification Water Supply

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• Source:
  Emerg Infect Dis. 8(1):29-36.
• Document Type:
  Journal Article
• Place as Subject:
  California
• Location:
  North America
• Volume:
  8
• Issue:
  1
• Collection(s):
  Emerging Infectious Diseases
• Main Document Checksum:
  urn:sha256:1f8a0e211d2edac0a671edd694c70378f36609408820f20d78da9a14a1a37969
• Download URL:
  https://stacks.cdc.gov/view/cdc/13744/cdc_13744_DS1.pdf
• File Type:
  [PDF - 78.16 KB ]