Context Immunization rates for children and adults remain below national goals.
While experts recommend that health care professionals remind patients of
needed immunizations, few practitioners actually use reminders. Little is
known about the effectiveness of reminders in different settings or patient
Objectives To assess the effectiveness of patient reminder systems in improving
immunization rates, and to compare the effectiveness of different types of
reminders for a variety of patient populations.
Data Sources A search was performed using MEDLINE, EMBASE, PsychINFO, Sociological
Abstracts, and CAB Health Abstracts. Relevant articles, as well as published
abstracts, conference proceedings, and files of study collaborators, were
searched for relevant references.
Study Selection and Data Extraction English-language studies involving patient reminder/recall interventions
(using criteria established by the Cochrane Collaboration) were eligible for
review if they involved randomized controlled trials, controlled before-after
studies, or interrupted time series, and measured immunization rates. Of 109
studies identified, 41 met eligibility criteria. Studies were reviewed independently
by 2 reviewers using a standardized checklist. Results of studies are expressed
as absolute percentage-point changes in immunization rates and as odds ratios
(ORs). Studies with similar characteristics of patients or interventions were
pooled (random effects model).
Data Synthesis Patient reminder systems were effective in improving immunization rates
in 33 (80%) of the 41 studies, irrespective of baseline immunization rates,
patient age, setting, or vaccination type. Increases in immunization rates
due to reminders ranged from 5 to 20 percentage points. Reminders were effective
for childhood vaccinations (OR, 2.02; 95% confidence interval [CI], 1.49-2.72),
childhood influenza vaccinations (OR, 4.25; 95% CI, 2.10-8.60), adult pneumococcus
or tetanus vaccinations (OR, 5.14; 95% CI, 1.21-21.78), 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, and telephone or autodialer calls), with telephone
reminders being most effective but costliest.
Conclusions Patient reminder systems in primary care settings are effective in improving
immunization rates. Primary care physicians should use patient reminders to
improve immunization delivery.