Assessing immunization rates in office practice

The impact of inactive infants on clinic-based immunization rates

OBJECTIVE

Clinic-based immunization rates are used to evaluate clinic performance and immunization interventions, but they typically exclude so-called inactive patients (ie, those who no longer receive care at the clinic). We assessed the effect of enhanced ascertainment of inactive patients on clinic-based immunization rates and on the conclusions of a randomized controlled trial.

METHODS

The study was a post hoc analysis of a cluster-randomized controlled trial. Infant randomization to the immunization intervention (4 clinics) or control group (4 clinics) was based on the site of their 2-week well-child care visit. The study was conducted at an integrated inner-city health care system serving a low-income population. A total of 2190 infants born between July 1, 1998, and June 30, 1999, who attended at least 1 postnatal visit, participated. In control sites, clinic staff documented inactive infants in the immunization registry and medical charts. The research staff undertook additional patient tracking efforts in the intervention clinics.

RESULTS

Control clinics identified 155 (13.4%) of 1160 children as inactive within 1 year of birth, whereas 284 (27.6%) of 1030 intervention infants were documented as inactive (P < .001). In bivariate analyses from the randomized trial, immunization rates differed between intervention and control branches. In multivariate models, immunization rates were significantly higher in the intervention branch when inactive infants were removed (adjusted relative risk 1.58; 95% confidence interval, 1.28-1.89), but not when they were included (adjusted relative risk 1.09; 95% confidence interval, 0.97-1.21).

CONCLUSIONS

Additional patient tracking efforts can dramatically influence inactive patient documentation and clinic-based immunization rates used for various purposes.

Preventive services: blood pressure checks at well child visits

The objective of this study was to determine rates of blood pressure (BP) screening at well-child visits as recommended by the Task Force on Blood Pressure Control in Children. The 1985 and 1996 National Ambulatory Medical Care Surveys were analyzed for changes in proportion of well visits for children aged 3-18 years at which BP was checked. Patient and physician demographics are described. BP screening increased from 50% in 1985 to 61% in 1996. For pediatricians, the estimates were 50% (95% CI, 43-57) and 60% (95% CI, 53-68). For family/general medicine the estimates were 51% (95% CI, 34-69) and 58% (95% CI, 43-74). Age, geographic location, and length of a visit were significant in predicting BP screening. Gender, race, ethnicity, or urban location were not. A stepwise logistic regression confirmed these results. Rates of screening BP at well-child visits have increased but fall short of current recommendations. High-risk children are not screened at a rate different from their lower risk peers.