Variation in clinician recommendations for multiple injections during adoption of inactivated polio vaccine.
OBJECTIVE
To describe variation in clinician recommendations for multiple injections during the adoption of inactivated poliovirus vaccine (IPV) in 2 large health maintenance organizations (HMOs), and to test the hypothesis that variation in recommendations would be associated with variation in immunization coverage rates.


METHODS
Cross-sectional study based on a survey of clinician practices 1 year after IPV was recommended and computerized immunization data from these clinicians' patients. STUDY SETTINGS: Two large West Coast HMOs: Kaiser Permanente in Northern California and Group Health Cooperative of Puget Sound.


METHODS
Immunization status of 8-month-olds and 24-month-olds cared for by the clinicians during the study.


RESULTS
More clinicians at Group Health (82%), where a central guideline was issued, had adopted the IPV/oral poliovirus vaccine (OPV) sequential schedule than at Kaiser (65%), where no central guideline was issued. Clinicians at both HMOs said that if multiple injections fell due at a visit and they elected to defer some vaccines, they would be most likely to defer the hepatitis B vaccine (HBV) for infants (40%). At Kaiser, IPV users were more likely than OPV users to recommend the first HBV at birth (64% vs 28%) or if they did not, to defer the third HBV to 8 months or later (62% vs 39%). In multivariate analyses, patients whose clinicians used IPV were as likely to be fully immunized at 8 months old as those whose clinicians used all OPV. At Kaiser, where there was variability in the maximum number of injections clinicians recommended at infant visits, providers who routinely recommended 3 or 4 injections at a visit had similar immunization coverage rates as those who recommended 1 or 2. At both HMOs, clinicians who strongly recommended all possible injections at a visit had higher immunization coverage rates at 8 months than those who offered parents the choice of deferring some vaccines to a subsequent visit (at Kaiser, odds ratio [OR]: 1.2; 95% confidence interval [CI]: 1.0-1.5; at Group Health, OR: 1.8; 95% CI: 1.1-2.8).


CONCLUSIONS
Neither IPV adoption nor the use of multiple injections at infant visits were associated with reductions in immunization coverage. However, at the HMO without centralized immunization guidelines, IPV adoption was associated with changes in the timing of the first and third HBV. Clinical policymakers should continue to monitor practice variation as future vaccines are added to the infant immunization schedule.
Lieu
T A
TA
Division of Research and the Vaccine Study Center, Kaiser Permanente, Oakland, California, USA. tracy_lieu@hphc.org
Davis
R L
RL
Capra
A M
AM
Mell
L K
LK
Quesenberry
C P
CP
Martin
K E
KE
Zavitkovsky
A
A
Black
S B
SB
Shinefield
H R
HR
Thompson
R S
RS
Rodewald
L E
LE
D002675:Child, Preschool; D003430:Cross-Sectional Studies; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines / Q000008:administration & dosage / Q000276:immunology; D006279:Health Maintenance Organizations / Q000458:organization & administration / Q000706:statistics & numerical data; D006302:Health Services Research; D006801:Humans; D007109:Immunity / Q000276:immunology; D007115:Immunization Schedule; D007223:Infant; D010372:Pediatrics; D011054:Poliovirus Vaccine, Inactivated / Q000008:administration & dosage* / Q000276:immunology; D017410:Practice Guidelines as Topic / Q000592:standards; D010818:Practice Patterns, Physicians'; D011795:Surveys and Questionnaires
D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines; D011054:Poliovirus Vaccine, Inactivated