Postcard reminders from GPs for influenza vaccine: are they more effective than an ad hoc approach?

A meta-analysis of influenza vaccination following correspondence: Considerations for COVID-19

Background

High vaccination rates are needed to protect against influenza and to end the COVID-19 pandemic. Health authorities need to know if supplementing mass communications with direct correspondence to the community would increase uptake.

Objectives

The primary objective is to determine if sending a single written message directly to individuals increases influenza vaccine uptake, and a secondary objective is to identify any identified content shown to increase influenza vaccine uptake.

Methods

MEDLINE, Embase, Cochrane CENTRAL, PsycINFO, and PubMed were searched for RCTs testing a single correspondence for members of the community in OECD countries to obtain influenza vaccination. A meta-analysis with inverse-variance, random-effects modelling was used to estimate a mean, weighted risk ratio effect size measure of vaccine uptake. Studies were quality assessed and analysis was undertaken to account for potential publication bias.

Results

Twenty-eight randomized controlled trials were included, covering 45 interventions. Of the 45 interventions, 37 (82.2%) report an increase in influenza vaccination rates. A formal meta-analysis shows that sending a single written message increased influenza vaccine uptake by 16%, relative to the no contact comparator group (RR = 1.16, 95% CI [1.13-1.20], Z = 9.25, p < .001). Analysis shows that the intervention is effective across correspondence type, age group, time, and location, and after allowing for risk of publication bias.

Limitations

The generalizability of results across the OECD may be questioned.

Conclusions and implications

The implication for public health authorities organizing vaccination programs for influenza, and arguably also for COVID-19, is that sending written vaccination correspondence to members of the community is likely to increase uptake. Keywords: vaccine uptake, COVID-19, influenza, direct correspondence, meta-analysis.

This study is pre-registered on osf.io; details can be found at https://osf.io/98mr7

Multiple mail reminders to increase adherence to influenza vaccination

INTRODUCTION

Different interventions have been proposed to reinforce the use of the influenza vaccine. The use of reminders, whether through letters, phone calls, pamphlets or technological applications, among others, has stood out among those aimed at increasing ad-herence to treatment. However, its effectiveness is not clear. In this summary, which is part of a series of reminder evaluations, we assess the use of multiple mail reminders.

METHODS

We conducted a search in Epistemonikos, the largest database of systematic health reviews, which is maintained by screening multiple sources of information, including MEDLINE, EMBASE, Cochrane, among others. We extracted the data from the identified reviews, analyzed the data from the primary studies, performed a meta-analysis and prepared a summary table of the results using the GRADE method.

RESULTS AND CONCLUSIONS

We identified eight systematic reviews including 35 primary studies, of which four analyze the use of more than one letter as a reminder. We conclude that the use of multiple mail reminders probably increase adherence to influenza vaccination in patients over 60; while it may make little or no difference in children under 6 years, but the certainty of the evidence is low.

Manually-generated reminders delivered on paper: effects on professional practice and patient outcomes

BACKGROUND

Health professionals sometimes do not use the best evidence to treat their patients, in part due to unconscious acts of omission and information overload. Reminders help clinicians overcome these problems by prompting them to recall information that they already know, or by presenting information in a different and more accessible format. Manually-generated reminders delivered on paper are defined as information given to the health professional with each patient or encounter, provided on paper, in which no computer is involved in the production or delivery of the reminder. Manually-generated reminders delivered on paper are relatively cheap interventions, and are especially relevant in settings where electronic clinical records are not widely available and affordable. This review is one of three Cochrane Reviews focused on the effectiveness of reminders in health care.

OBJECTIVES

1. To determine the effectiveness of manually-generated reminders delivered on paper in changing professional practice and improving patient outcomes. 2. To explore whether a number of potential effect modifiers influence the effectiveness of manually-generated reminders delivered on paper.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL and two trials registers on 5 December 2018. We searched grey literature, screened individual journals, conference proceedings and relevant systematic reviews, and reviewed reference lists and cited references of included studies.

SELECTION CRITERIA

We included randomised and non-randomised trials assessing the impact of manually-generated reminders delivered on paper as a single intervention (compared with usual care) or added to one or more co-interventions as a multicomponent intervention (compared with the co-intervention(s) without the reminder component) on professional practice or patients' outcomes. We also included randomised and non-randomised trials comparing manually-generated reminders with other quality improvement (QI) interventions.

DATA COLLECTION AND ANALYSIS

Two review authors screened studies for eligibility and abstracted data independently. We extracted the primary outcome as defined by the authors or calculated the median effect size across all reported outcomes in each study. We then calculated the median percentage improvement and interquartile range across the included studies that reported improvement related outcomes, and assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We identified 63 studies (41 cluster-randomised trials, 18 individual randomised trials, and four non-randomised trials) that met all inclusion criteria. Fifty-seven studies reported usable data (64 comparisons). The studies were mainly located in North America (42 studies) and the UK (eight studies). Fifty-four studies took place in outpatient/ambulatory settings. The clinical areas most commonly targeted were cardiovascular disease management (11 studies), cancer screening (10 studies) and preventive care (10 studies), and most studies had physicians as their target population (57 studies). General management of a clinical condition (17 studies), test-ordering (14 studies) and prescription (10 studies) were the behaviours more commonly targeted by the intervention. Forty-eight studies reported changes in professional practice measured as dichotomous process adherence outcomes (e.g. compliance with guidelines recommendations), 16 reported those changes measured as continuous process-of-care outcomes (e.g. number of days with catheters), eight reported dichotomous patient outcomes (e.g. mortality rates) and five reported continuous patient outcomes (e.g. mean systolic blood pressure). Manually-generated reminders delivered on paper probably improve professional practice measured as dichotomous process adherence outcomes) compared with usual care (median improvement 8.45% (IQR 2.54% to 20.58%); 39 comparisons, 40,346 participants; moderate certainty of evidence) and may make little or no difference to continuous process-of-care outcomes (8 comparisons, 3263 participants; low certainty of evidence). Adding manually-generated paper reminders to one or more QI co-interventions may slightly improve professional practice measured as dichotomous process adherence outcomes (median improvement 4.24% (IQR -1.09% to 5.50%); 12 comparisons, 25,359 participants; low certainty of evidence) and probably slightly improve professional practice measured as continuous outcomes (median improvement 0.28 (IQR 0.04 to 0.51); 2 comparisons, 12,372 participants; moderate certainty of evidence). Compared with other QI interventions, manually-generated reminders may slightly decrease professional practice measured as process adherence outcomes (median decrease 7.9% (IQR -0.7% to 11%); 14 comparisons, 21,274 participants; low certainty of evidence). We are uncertain whether manually-generated reminders delivered on paper, compared with usual care or with other QI intervention, lead to better or worse patient outcomes (dichotomous or continuous), as the certainty of the evidence is very low (10 studies, 13 comparisons). Reminders added to other QI interventions may make little or no difference to patient outcomes (dichotomous or continuous) compared with the QI alone (2 studies, 2 comparisons). Regarding resource use, studies reported additional costs per additional point of effectiveness gained, but because of the different currencies and years used the relevance of those figures is uncertain. None of the included studies reported outcomes related to harms or adverse effects.

AUTHORS' CONCLUSIONS

Manually-generated reminders delivered on paper as a single intervention probably lead to small to moderate increases in outcomes related to adherence to clinical recommendations, and they could be used as a single QI intervention. It is uncertain whether reminders should be added to other QI intervention already in place in the health system, although the effects may be positive. If other QI interventions, such as patient or computerised reminders, are available, they should be preferred over manually-generated reminders, but under close evaluation in order to decrease uncertainty about their potential effect.

Interventions to increase influenza vaccination rates of those 60 years and older in the community

BACKGROUND

The effectiveness of interventions to increase influenza vaccination uptake in people aged 60 years and older varies by country and participant characteristics. This review updates versions published in 2010 and 2014.

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 METHODS

We searched CENTRAL, which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE, Embase, CINAHL, and ERIC for this update, as well as WHO ICTRP and ClinicalTrials.gov for ongoing studies to 7 December 2017. We also searched the reference lists of included studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and cluster-randomised trials of interventions to increase influenza vaccination in people aged 60 years or older in the community.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as specified by Cochrane.

MAIN RESULTS

We included three new RCTs for this update (total 61 RCTs; 1,055,337 participants). Trials involved people aged 60 years and older living in the community in high-income countries. Heterogeneity limited some meta-analyses. We assessed studies as at low risk of bias for randomisation (38%), allocation concealment (11%), blinding (44%), and selective reporting (100%). Half (51%) had missing data. We assessed the evidence as low-quality. We identified three levels of intervention intensity: low (e.g. postcards), medium (e.g. personalised phone calls), and high (e.g. home visits, facilitators).Increasing community demand (12 strategies, 41 trials, 53 study arms, 767,460 participants)One successful intervention that could be meta-analysed was client reminders or recalls by letter plus leaflet or postcard compared to reminder (odds ratio (OR) 1.11, 95% confidence interval (CI) 1.07 to 1.15; 3 studies; 64,200 participants). Successful interventions tested by single studies were patient outreach by retired teachers (OR 3.33, 95% CI 1.79 to 6.22); invitations by clinic receptionists (OR 2.72, 95% CI 1.55 to 4.76); nurses or pharmacists educating and nurses vaccinating patients (OR 152.95, 95% CI 9.39 to 2490.67); medical students counselling patients (OR 1.62, 95% CI 1.11 to 2.35); and multiple recall questionnaires (OR 1.13, 95% CI 1.03 to 1.24).Some interventions could not be meta-analysed due to significant heterogeneity: 17 studies tested simple reminders (11 with 95% CI entirely above unity); 16 tested personalised reminders (12 with 95% CI entirely above unity); two investigated customised compared to form letters (both 95% CI above unity); and four studies examined the impact of health risk appraisals (all had 95% CI above unity). One study of a lottery for free groceries was not effective.Enhancing vaccination access (6 strategies, 8 trials, 10 arms, 9353 participants)We meta-analysed results from two studies of home visits (OR 1.30, 95% CI 1.05 to 1.61) and two studies that tested free vaccine compared to patient payment for vaccine (OR 2.36, 95% CI 1.98 to 2.82). We were unable to conduct meta-analyses of two studies of home visits by nurses plus a physician care plan (both with 95% CI above unity) and two studies of free vaccine compared to no intervention (both with 95% CI above unity). One study of group visits (OR 27.2, 95% CI 1.60 to 463.3) was effective, and one study of home visits compared to safety interventions was not.Provider- or system-based interventions (11 strategies, 15 trials, 17 arms, 278,524 participants)One successful intervention that could be meta-analysed focused on payments to physicians (OR 2.22, 95% CI 1.77 to 2.77). Successful interventions tested by individual studies were: reminding physicians to vaccinate all patients (OR 2.47, 95% CI 1.53 to 3.99); posters in clinics presenting vaccination rates and encouraging competition between doctors (OR 2.03, 95% CI 1.86 to 2.22); and chart reviews and benchmarking to the rates achieved by the top 10% of physicians (OR 3.43, 95% CI 2.37 to 4.97).We were unable to meta-analyse four studies that looked at physician reminders (three studies with 95% CI above unity) and three studies of facilitator encouragement of vaccination (two studies with 95% CI above unity). Interventions that were not effective were: comparing letters on discharge from hospital to letters to general practitioners; posters plus postcards versus posters alone; educational reminders, academic detailing, and peer comparisons compared to mailed educational materials; educational outreach plus feedback to teams versus written feedback; and an intervention to increase staff vaccination rates.Interventions at the societal levelNo studies reported on societal-level interventions.Study funding sourcesStudies were funded by government health organisations (n = 33), foundations (n = 9), organisations that provided healthcare services in the studies (n = 3), and a pharmaceutical company offering free vaccines (n = 1). Fifteen studies did not report study funding sources.

AUTHORS' CONCLUSIONS

We identified interventions that demonstrated significant positive effects of low (postcards), medium (personalised phone calls), and high (home visits, facilitators) intensity that increase community demand for vaccination, enhance access, and improve provider/system response. The overall GRADE assessment of the evidence was moderate quality. Conclusions are unchanged from the 2014 review.

Patient reminder and recall interventions to improve immunization rates

BACKGROUND

Immunization rates for children and adults are rising, but coverage levels have not reached optimal goals. As a result, vaccine-preventable diseases still occur. In an era of increasing complexity of immunization schedules, rising expectations about the performance of primary care, and large demands on primary care providers, it is important to understand and promote interventions that work in primary care settings to increase immunization coverage. One common theme across immunization programs in many nations involves the challenge of implementing a population-based approach and identifying all eligible recipients, for example the children who should receive the measles vaccine. However, this issue is gradually being addressed through the availability of immunization registries and electronic health records. A second common theme is identifying the best strategies to promote high vaccination rates. Three types of strategies have been studied: (1) patient-oriented interventions, such as patient reminder or recall, (2) provider interventions, and (3) system interventions, such as school laws. One of the most prominent intervention strategies, and perhaps best studied, involves patient reminder or recall systems. This is an update of a previously published review.

OBJECTIVES

To evaluate and compare the effectiveness of various types of patient reminder and recall interventions to improve receipt of immunizations.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and CINAHL to January 2017. We also searched grey literature and trial registers to January 2017.

SELECTION CRITERIA

We included randomized trials, controlled before and after studies, and interrupted time series evaluating immunization-focused patient reminder or recall interventions in children, adolescents, and adults who receive immunizations in any setting. We included no-intervention control groups, standard practice activities that did not include immunization patient reminder or recall, media-based activities aimed at promoting immunizations, or simple practice-based awareness campaigns. We included receipt of any immunizations as eligible outcome measures, excluding special travel immunizations. We excluded patients who were hospitalized for the duration of the study period.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane and the Cochrane Effective Practice and Organisation of Care (EPOC) Group. We present results for individual studies as relative rates using risk ratios, and risk differences for randomized trials, and as absolute changes in percentage points for controlled before-after studies. We present pooled results for randomized trials using the random-effects model.

MAIN RESULTS

The 75 included studies involved child, adolescent, and adult participants in outpatient, community-based, primary care, and other settings in 10 countries.Patient reminder or recall interventions, including telephone and autodialer calls, letters, postcards, text messages, combination of mail or telephone, or a combination of patient reminder or recall with outreach, probably improve the proportion of participants who receive immunization (risk ratio (RR) of 1.28, 95% confidence interval (CI) 1.23 to 1.35; risk difference of 8%) based on moderate certainty evidence from 55 studies with 138,625 participants.Three types of single-method reminders improve receipt of immunizations based on high certainty evidence: the use of postcards (RR 1.18, 95% CI 1.08 to 1.30; eight studies; 27,734 participants), text messages (RR 1.29, 95% CI 1.15 to 1.44; six studies; 7772 participants), and autodialer (RR 1.17, 95% CI 1.03 to 1.32; five studies; 11,947 participants). Two types of single-method reminders probably improve receipt of immunizations based on moderate certainty evidence: the use of telephone calls (RR 1.75, 95% CI 1.20 to 2.54; seven studies; 9120 participants) and letters to patients (RR 1.29, 95% CI 1.21 to 1.38; 27 studies; 81,100 participants).Based on high certainty evidence, reminders improve receipt of immunizations for childhood (RR 1.22, 95% CI 1.15 to 1.29; risk difference of 8%; 23 studies; 31,099 participants) and adolescent vaccinations (RR 1.29, 95% CI 1.17 to 1.42; risk difference of 7%; 10 studies; 30,868 participants). Reminders probably improve receipt of vaccinations for childhood influenza (RR 1.51, 95% CI 1.14 to 1.99; risk difference of 22%; five studies; 9265 participants) and adult influenza (RR 1.29, 95% CI 1.17 to 1.43; risk difference of 9%; 15 studies; 59,328 participants) based on moderate certainty evidence. They may improve receipt of vaccinations for adult pneumococcus, tetanus, hepatitis B, and other non-influenza vaccinations based on low certainty evidence although the confidence interval includes no effect of these interventions (RR 2.08, 95% CI 0.91 to 4.78; four studies; 8065 participants).

AUTHORS' CONCLUSIONS

Patient reminder and recall systems, in primary care settings, are likely to be effective at improving the proportion of the target population who receive immunizations.

Interventions to increase influenza vaccination rates of those 60 years and older in the community

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 METHODS

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.

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.

Interventions to increase influenza vaccination rates of those 60 years and older in the community

BACKGROUND

Although the evidence to support influenza vaccination is poor, it is promoted by many health authorities. There is uncertainty about the effectiveness of interventions to increase influenza vaccination rates in those 60 years or older.

OBJECTIVES

To assess effects of interventions to increase influenza vaccination rates in those 60 or older.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2010, issue 3), containing the Cochrane Acute Respiratory Infections Group's Specialized Register, MEDLINE (January 1950 to July 2010), PubMed (January 1950 to July 2010), EMBASE (1980 to 2010 Week 28), AgeLine (1978 to July 2010), ERIC (1965 to July 2010) and CINAHL (1982 to July 2010).

SELECTION CRITERIA

Randomized controlled trials (RCTs) to increase influenza vaccination rates in those aged 60 years and older, recording influenza vaccination status either through clinic records, billing data or local/national vaccination registers.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and extracted data.

MAIN RESULTS

Forty-four RCTs were included. All included RCTs studied seniors in the community and in high-income countries. No RCTs of society-level interventions were included. Heterogeneity was marked and meta-analysis was limited. Only five RCTs were graded at low and six at moderate risk of bias. They included three of 13 personalized postcard interventions (all three with the 95% confidence interval (CI) above unity), two of the four home visit interventions (both with 95% CI above unity, but one a small study), three of the four reminder to physicians interventions (none with 95% CI above unity) and three of the four facilitator interventions (one with 95% CI above unity, and one P < 0.01). The other 33 RCTs were at high risk of bias and no recommendations for practice can be drawn.

AUTHORS' CONCLUSIONS

Personalized postcards or phone calls are effective, and home visits, and facilitators, may be effective. Reminders to physicians are not. There is insufficient good evidence for other interventions.

Patient reminder and patient recall systems to improve immunization rates

BACKGROUND

Immunization rates for children and adults are rising, but coverage levels have not reached optimal goals. As a result of low immunization rates, vaccine-preventable diseases still occur. In an era of increasing complexity of immunization schedules, rising expectations about the performance of primary care and large demands on primary care physicians, it is important to understand and promote interventions that work in primary care settings to increase immunization coverage. A common theme across immunization programs in all nations involves the challenge of determining the denominator of eligible recipients (e.g. all children who should receive the measles vaccine) and identifying the best strategy to ensure high vaccination rates. Strategies have focused on patient-oriented interventions (e.g., patient reminders), provider interventions and system interventions. One intervention strategy involves patient reminder and recall systems.

OBJECTIVES

To assess the effectiveness of patient reminder and recall systems in improving immunization rates and compare the effects of various types of reminders in different settings or patient populations.

SEARCH STRATEGY

A systematic search was performed for the initial review using MEDLINE (1966-1998) and four other bibliographic databases: EMBASE, PsychINFO, Sociological Abstracts, and CAB Abstracts. Authors also performed a search of The Effective Practice and Organisation of Care (EPOC) register in April 2001 to update the review. Two authors reviewed the lists of titles and abstracts and used the inclusion criteria to mark potentially relevant articles for full review. The reference lists of all relevant articles and reviews were back searched for additional studies. Publications of abstracts, proceedings from scientific meetings and files of study collaborators were also searched for references. In December 2004 the EPOC register was searched to identify relevant articles to update the review.

STUDY DESIGN

Randomized controlled trials (RCT), controlled before and after studies (CBA) and interrupted time series (ITS) studies written in English.

TYPES OF PARTICIPANTS

Health care personnel who deliver immunizations and children (birth to 18 years) or adults (18 years and up) who receive immunizations in any setting.

TYPES OF INTERVENTIONS

Any intervention that falls within the EPOC scope (See Group Details) and that includes patient reminder or recall systems, or both, in at least one arm of the study.

TYPES OF OUTCOME MEASURES

Immunization rates or the proportion of the target population up-to-date on recommended immunizations. Outcomes were acceptable for either individual vaccinations (e.g. influenza vaccination) or standard combinations of recommended vaccinations (e.g. all recommended vaccinations by a specific date or age).

DATA COLLECTION

Each study was read independently by two reviewers. Disagreements between reviewers were resolved by a formal reconciliation process to achieve consensus.

ANALYSIS

Results are presented for individual studies as relative rates for randomized controlled trials and as absolute changes in percentage points for controlled before and after studies. Pooled results for RCTs only were presented using the random effects model.

MAIN RESULTS

Five new studies were added for this update. Increases in immunization rates due to reminders were in the range of 1 to 20 percentage points. Reminders were effective for childhood vaccinations (OR = 1.45, 95% CI =1.28, 1.66), childhood influenza vaccinations (OR = 2.87, 95% CI = 1.65, 4.98), adult pneumococcus, tetanus, and Hepatitis B (OR = 2.19, 95% CI = 1.21, 3.99), and adult influenza vaccinations (OR = 1.66, 95% CI = 1.31, 2.09). All types of reminders were effective (postcards, letters, telephone or autodialer calls), with telephone being the most effective but most costly.

AUTHORS' CONCLUSIONS

Patient reminder and recall systems in primary care settings are effective in improving immunization rates within developed countries.

Interventions aimed at improving immunization rates

BACKGROUND

Immunization rates for children and adults are rising, but coverage levels have not reached national goals. As a result of low immunization rates, vaccine-preventable diseases still occur. In an era of increasing complexity of immunization schedules, rising expectations about the performance of primary care, and large demands on primary care physicians, it is important to understand and promote interventions that work in primary care settings to increase immunization coverage. A common theme across immunization programs in all nations involves the challenge of determining the denominator of eligible recipients (e.g., all children who should receive the measles vaccine), and identifying the best strategy to ensure high vaccination rates. Strategies have focused on patient-oriented interventions (e.g., patient reminders), provider interventions, and system interventions. One intervention strategy involves patient reminder/recall systems.

OBJECTIVES

Assess the effectiveness of patient reminder/recall systems in improving immunization rates, and compare the effects of various types of reminders in different settings or patient populations.

SEARCH STRATEGY

A systematic search was performed using MEDLINE (1966-1998) and 4 other bibliographic databases: EMBASE, PsychINFO, Sociological Abstracts, and CAB Abstracts. Authors also performed a search of EPOC in April 2001 to update the review. Two authors reviewed the lists of titles and abstracts, and used the inclusion criteria to mark potentially relevant articles for full review. The reference lists of all relevant articles and reviews were back searched for additional studies. Publications of abstracts, proceedings from scientific meetings, and files of study collaborators were also searched for references.

STUDY DESIGN

Randomized controlled trials (RCT), controlled before and after studies (CBA), and interrupted time series (ITS) studies written in English.

TYPES OF PARTICIPANTS

Health care personnel who deliver immunizations and children (birth to 18 years) or adults (18 years and up) who receive immunizations in any setting. Types of interventions: Any intervention that falls within the Effective Practice and Organization of Care Group (EPOC) scope and that includes patient reminder and/or recall in at least one arm of the study. Types of outcome measures: Immunization rates, or the proportion of the target population up-to-date on recommended immunizations. Outcomes were acceptable for either individual vaccinations (e.g., influenza vaccination) or standard combinations of recommended vaccinations (e.g., all recommended vaccinations by a specific date or age).

DATA COLLECTION

Each study was read independently by two reviewers. Disagreements between reviewers were resolved by a formal reconciliation process to achieve consensus.

ANALYSIS

Results are presented for individual studies as relative rates for randomized controlled trials, and as absolute changes in percentage points for controlled before and after studies. Pooled results were presented using the random effects model.

MAIN RESULTS

Patient reminder/recall systems were effective in improving immunization rates in 33 of 41 included studies, irrespective of baseline immunization rates, patient ages, type of setting, or type of vaccination. Increases in immunization rates due to reminders were in the range of 5 to 20 percentage points. Reminders were effective for childhood vaccinations (OR=2.02, 95% CI =1.49,2.72), childhood influenza vaccinations (OR=4.19, 95% CI =2.07,8.49), adult pneumococcus or tetanus (OR=5.14, 95%CI = 1.21, 21.8), and adult influenza vaccinations (OR=2.29, 95%CI = 1.69, 3.10). While reminders were most effective in academic settings (OR = 3.33, 95% CI = 1.98, 5.58), they were also highly effective in private practice settings (OR=1.79, 95% CI = 1.45, 2.22) and public health clinics (OR = 2.09, 95% CI = 1.42, 3.07). All types of reminders were effective (postcards, letters, telephone or autodialer calls), with telephone being the most effective but most costly.

REVIEWER'S CONCLUSIONS

Patient reminder/recall systems in primary care settings are effective in improving immunization rates.