Moran 1996

Methods	Purpose: "To determine whether an educational brochure or a lottery‐type incentive increases influenza immunization rates." Design: RCT ‐ patients randomised Duration of study: 3 months Power computation: not reported Statistics: Chi2, Wilcoxon, logistic regression, odds ratios with CI, percentage patients receiving influenza vaccination in 4 groups
Participants	Country: United States Setting: urban community health centre Participants: "All high‐risk ambulatory patients seen at the community health centre within the preceding 18 months" Age: > 18 to 99 years of age, mean age 66 (n = 797) Gender: male and female
Interventions	Patients were randomly assigned to 1 of 4 groups: control (n = 202), mailed educational brochure (n = 198), mailed lottery incentive wherein patients who obtained an influenza vaccination would be eligible to win 1 of 3 grocery gift certificates (n = 198), and a mailed combined educational brochure and lottery incentive (n = 199)
Outcomes	Odds ratio of patients in the 4 groups obtaining an influenza vaccination. Odds ratio for patients in the brochure group obtaining influenza immunisation when compared with the control (odds ratio 2.29, 95% CI 1.45 to 3.61), odds ratio for incentive group compared with control: (OR = 1.68, 95% CI 1.05 to 2.68). "Immunization for the group mailed both interventions was not significantly different from control (OR = 1.41, 95% confidence interval CI 0.88‐2.27). For the subset of individuals for whom prior immunization status was known, the impact of the educational brochure was even more significant (OR = 3.95,95% CI 1.92 to S.lO), but the groups mailed incentive or both interventions were not significantly different". For those aged 65+, the study reports on the percentage in each group that received vaccination: 25% control, 41% brochure, 30% incentive, 24% brochure and incentive
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"High‐risk patients were randomly allocated to one of four groups." (no statement about method of randomisation)
Allocation concealment (selection bias)	Unclear risk	No statement
Blinding (performance bias and detection bias) All outcomes	Unclear risk	No statement
Incomplete outcome data (attrition bias) All outcomes	Low risk	"... all high‐risk patients (n = 797) seen in the preceding 18 months" were reported in the final outcome (Table II)
Selective reporting (reporting bias)	Low risk	No selective reporting