The effect of a combined influenza/pneumococcal immunization reminder letter.
BACKGROUND
The effect of a combined influenza and pneumococcal immunization reminder letter on increasing influenza and pneumococcal immunization rates, and the timeliness of receiving immunizations after receipt of a reminder letter, have not been examined. This study addresses these issues using a sample of new Medicare beneficiaries residing in Hawaii.


METHODS
Newly enrolled Medicare beneficiaries in Hawaii from 25 September 1995 through 31 August 1996 were randomly assigned to one of three groups: Group 1, no letter (n=2144); Group 2, influenza immunization reminder letter only (n=2213); or Group 3, pneumococcal and influenza immunization reminder letter (n=2171). Health Care Financing Administration claims data were compared among groups.


RESULTS
In Group 3, the influenza immunization rate increased 3.8 percentage points (n=87; p=0.017) compared with Group 1. The Group 3 pneumococcal immunization rate increased 3.5 percentage points (n=78; p<0.001) compared to Group 1 and 4.0 percentage points (n=86; p<0.001) compared to Group 2. Sixty-six beneficiaries in Group 3 received simultaneous pneumococcal and influenza immunizations, a significant difference compared to Group 1 or Group 2. Increases in immunizations were observed immediately following the reminder letters and the effect persisted for 5 to 7 weeks.


CONCLUSIONS
The combination letter increased both influenza and pneumococcal immunization rates and the simultaneous administration of immunizations without detrimental effect to influenza immunization rates. A combined reminder letter is inexpensive and recommended as part of a multicomponent campaign for adult immunization.
Terrell-Perica
S M
SM
National Immunization Program, Centers for Disease Control and Prevention, Atlanta, Georgia, USA. smdterre@mail.health.state.hi.us
Effler
P V
PV
Houck
P M
PM
Lee
L
L
Crosthwaite
G H
GH
D000368:Aged; D005260:Female; D006254:Hawaii; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000191:economics*; D008297:Male; D006278:Medicare; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000191:economics*; D017010:Reminder Systems / Q000191:economics*
D007252:Influenza Vaccines; D022242:Pneumococcal Vaccines