Interventions to increase influenza (flu) vaccination uptake for people aged 60 and older

Many health authorities recommend influenza vaccination of older people. However, vaccination uptake in people aged 60 and older varies across countries, socioeconomic and health-risk groups. It is important to identify effective interventions to increase influenza vaccination uptake.

We included 57 randomised controlled trials (RCTs) with 896,531 participants (all were community-dwelling seniors in high-income countries). Thirty-six trials compared the intervention to a no-intervention control group. Of the 57 RCTs, 33% randomised participants using a method that produced a low risk of bias and 61% used a method with an unclear risk. For missing data, 49% of the RCTs had a low risk of bias and 39% had an unclear risk.

Included trials all focused on increasing influenza vaccination uptake and did not report adverse effects. Trials were varied and we needed to use caution when pooling results.

Increasing community demand for vaccination (32 trials, 10 strategies)

Effective interventions in this comparison were a letter plus leaflet/postcard compared to a letter, nurses/pharmacists educating plus vaccinating patients, a phone call from a senior, a telephone invitation rather than clinic drop-in, free groceries lottery, and nurses educating and vaccinating patients. We were unable to pool trials of postcard/letter/pamphlets, communications tailored to patients, a customised letter/phone-call or client-based appraisals, but several trials of these interventions showed they were effective.

Enhancing vaccination access (eight trials, six strategies)

Effective interventions in this comparison were: home visits compared to an invitation to attend clinic, offers of free vaccine (in USA) and patient group-visits to physicians. We were unable to pool trials of nurse home-visits or free vaccine compared to no intervention (USA).

Improving provision by providers or the healthcare system (17 trials, 11 strategies)

Effective interventions in this comparison were: paying physicians, reminding physicians about all patients, posters plus postcards, chart review/feedback and educational outreach/feedback.

Trials of posters plus postcards versus posters, academic detailing and increasing staff vaccination rates showed that these interventions were not effective.

We did not pool the following trials due to considerable heterogeneity: reminding physicians (four trials, n = 202,264) and practice facilitators, although several of these trials showed the interventions were effective.

We found no low risk of bias RCTs or cohort studies that studied whether these interventions reduce morbidity or hospitalisation of seniors.

Evidence is current to 4 June 2014.

Societal level: No RCTs

Authors' conclusions: 

There are interventions that are effective for increasing community demand for vaccination, enhancing access and improving provider/system response. Heterogeneity limited pooling of trials.

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Background: 

The effectiveness of interventions to increase the uptake of influenza vaccination in people aged 60 and older is uncertain.

Objectives: 

To assess access, provider, system and societal interventions to increase the uptake of influenza vaccination in people aged 60 years and older in the community.

Search strategy: 

We searched CENTRAL (2014, Issue 5), MEDLINE (January 1950 to May week 3 2014), EMBASE (1980 to June 2014), AgeLine (1978 to 4 June 2014), ERIC (1965 to June 2014) and CINAHL (1982 to June 2014).

Selection criteria: 

Randomised controlled trials (RCTs) of interventions to increase influenza vaccination uptake in people aged 60 and older.

Data collection and analysis: 

Two review authors independently assessed study quality and extracted influenza vaccine uptake data.

Main results: 

This update identified 13 new RCTs; the review now includes a total of 57 RCTs with 896,531 participants. The trials included community-dwelling seniors in high-income countries. Heterogeneity limited meta-analysis. The percentage of trials with low risk of bias for each domain was as follows: randomisation (33%); allocation concealment (11%); blinding (44%); missing data (49%) and selective reporting (100%).

Increasing community demand (32 trials, 10 strategies)

The interventions with a statistically significant result were: three trials (n = 64,200) of letter plus leaflet/postcard compared to letter (odds ratio (OR) 1.11, 95% confidence interval (CI) 1.07 to 1.15); two trials (n = 614) of nurses/pharmacists educating plus vaccinating patients (OR 3.29, 95% CI 1.91 to 5.66); single trials of a phone call from a senior (n = 193) (OR 3.33, 95% CI 1.79 to 6.22), a telephone invitation versus clinic drop-in (n = 243) (OR 2.72, 95% CI 1.55 to 4.76), a free groceries lottery (n = 291) (OR 1.04, 95% CI 0.62 to 1.76) and nurses educating and vaccinating patients (n = 485) (OR 152.95, 95% CI 9.39 to 2490.67).

We did not pool the following trials due to considerable heterogeneity: postcard/letter/pamphlets (16 trials, n = 592,165); tailored communications (16 trials, n = 388,164); customised letter/phone-call (four trials, n = 82,465) and client-based appraisals (three trials, n = 4016), although several trials showed the interventions were effective.

Enhancing vaccination access (10 trials, six strategies)

The interventions with a statistically significant result were: two trials (n = 2112) of home visits compared to clinic invitation (OR 1.30, 95% CI 1.05 to 1.61); two trials (n = 2251) of free vaccine (OR 2.36, 95% CI 1.98 to 2.82) and one trial (n = 321) of patient group visits (OR 24.85, 95% CI 1.45 to 425.32). One trial (n = 350) of a home visit plus vaccine encouragement compared to a home visit plus safety advice was non-significant.

We did not pool the following trials due to considerable heterogeneity: nurse home visits (two trials, n = 2069) and free vaccine compared to no intervention (two trials, n = 2250).

Provider- or system-based interventions (17 trials, 11 strategies)

The interventions with a statistically significant result were: two trials (n = 2815) of paying physicians (OR 2.22, 95% CI 1.77 to 2.77); one trial (n = 316) of reminding physicians about all their patients (OR 2.47, 95% CI 1.53 to 3.99); one trial (n = 8376) of posters plus postcards (OR 2.03, 95% CI 1.86 to 2.22); one trial (n = 1360) of chart review/feedback (OR 3.43, 95% CI 2.37 to 4.97) and one trial (n = 27,580) of educational outreach/feedback (OR 0.77, 95% CI 0.72 to 0.81).

Trials of posters plus postcards versus posters (n = 5753), academic detailing (n = 1400) and increasing staff vaccination rates (n = 26,432) were non-significant.

We did not pool the following trials due to considerable heterogeneity: reminding physicians (four trials, n = 202,264) and practice facilitators (three trials, n = 2183), although several trials showed the interventions were effective.

Interventions at the societal level

We identified no RCTs of interventions at the societal level.

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