Methods |
Purpose: to compare the effect of a mailed educational brochure on influenza vaccination uptake compared to no intervention Design: RCT, participants as unit of randomisation Duration of study: 4 months Interval between intervention and when outcome was measured: "The educational brochures were mailed to the intervention group when the influenza vaccine became available at the beginning of October." (Year not stated) Power computation: 900 participants required to detect 20% difference if baseline rate 20%, 90% power, α = 0.05 Statistics: not stated (probabilities computed) |
Participants |
Country: USA Setting: general internal medicine and gerontology service, Wake Forest University, N. Carolina Eligible participants: (health status): 1583, then excluded residents of long‐term care facilities, leaving 1251, of whom 900 were randomised to treatment and control groups Age: ≥ 65; avg = 76 Gender: 65.4% f |
Interventions |
Intervention: mailed brochure encouraging influenza vaccination Control: no intervention |
Outcomes |
Outcome measured: % vaccinated Time points from the study that are considered in the review or measured or reported in the study: October to following January (year not stated) % vaccinated by: January following intervention in October |
Notes |
Funding: National Institute on Aging |
Risk of bias |
Bias |
Authors' judgement |
Support for judgement |
Random sequence generation (selection bias) |
Unclear risk |
"... two random samples of 450 were selected for the intervention and control groups." |
Allocation concealment (selection bias) |
Unclear risk |
No statement |
Blinding (performance bias and detection bias) All outcomes |
Unclear risk |
No statement, vaccination status entered on computer clinical tracking program |
Incomplete outcome data (attrition bias) All outcomes |
Unclear risk |
Clinic immunisation and financial logs showed 80 in intervention and 71 in control group received influenza vaccination; 666/900 responded to the postcard survey and a total of 218 in intervention group said had been vaccinated in clinic and elsewhere and 213 in control |
Selective reporting (reporting bias) |
Low risk |
No selective reporting |