Effect of Physician Asthma Education on Health Care Utilization of Children at Different Income Levels Randall Brown, Noreen Clark, Niko Kaciroti, Molly Gong, Michael Cabana, Juanita Lyons University of Michigan Funded by NHLBI Grant #HL44976 May 2002

Background This is a substudy of a randomly controlled trial to assess patient outcomes resulting from asthma care education for their physicians. The education was an interactive seminar designed to enhance physicians’ therapeutic skills in treating children with asthma and to develop their capacity to educate and counsel families about asthma self-management.

Purpose The purpose of this substudy was to examine program effect on hospital admissions and emergency department visits among children of different income levels.

Methods Data Collection Patients’ telephone interview: Data was collected at baseline, within a 22- month window following the first visit to their physician subsequent to the seminar, and 12 months thereafter.

Samples

Physician Characteristics Gender Female 40% Male 60% Age % % % 60 and older 14%

Patient Characteristics Girls 30% Gender Girls 30% African American 15% Race/Ethnicity

Patient Characteristics > College 14% High School 22% Household Income K 22% K 20% K 19% > 80 K 19% < 20 K 20% High School 22% > College 14% < High School 22% Parent Education Level

Data Analysis Technique Models were derived from Poisson regressions with generalized estimated equation (GEE) analyses covering three periods: baseline to 12-months, 12 to 24- months, and baseline to 24 months.

Parameters Previous response regarding the outcome variables of interest and prior and current inhaled anti-inflammatory medication use were controlled in each model. An interaction (program participation x income, coded as levels 1 to 11 from low to high mean = 7.1), and program participation were included to examine if the effect of the intervention differed according to income level.

The Model Number of ED/Hospitalizations at Follow-up 1 or Follow-up 2 + Baseline score or first Follow-up score + Program participation + Income + Inhaled medication use at Baseline + Inhaled medication use at Follow-up 1 or Follow-up 2 + Interaction term of program participation x income

Results Table 1. Adjusted Yearly Rate of Hospitalizations for Families of Different Income Levels * Yearly rates were calculated using the following formulae: Yearly rate = e k x 365 k = intercept + b1 x mean Baseline or Follow-up 1 score + b2 x program participation + b3 x income + b4 x medication use + b5 x interaction of income x program participation

Table 2. Adjusted Yearly Rate of ED Visits for Families of Different Income Levels * Yearly rates were calculated using the following formulae: Yearly rate = e k x 365 k = intercept + b1 x mean Baseline or Follow-up 1 score + b2 x program participation + b3 x income + b4 x medication use + b5 x interaction of income x program participation Results

Table 3. Estimates and p-values for Program Participation and Interaction of Program Participation and Income Baseline to Follow-up 1 * Regardless of family income, the effects of physician education on health care utilization were not revealed from Baseline to Follow-up 1.

Results Table 4. Estimates and p-values for Program Participation and Interaction of Program Participation and Income Follow-up 1 to Follow-up 2 * Regardless of family income, children whose physicians were in the intervention group had significantly fewer hospital admissions from Follow-up 1 to Follow-up 2. ** The education for physicians was significantly effective in reducing ED visits for lower income children from Follow-up 1 to Follow-up 2.

Results Table 5. Estimates and p-values for Program Participation and Interaction of Program Participation and Income Baseline to Follow-up 2 * Regardless of family income, children whose physicians were in the intervention group showed a strong trend toward fewer hospital admissions from Baseline to Follow-up 2. ** The education for physicians was effective in reducing ED visits at lower income levels from Baseline to Follow-up 2.

Conclusions 1. The education interactive seminar for physicians did not effect hospital admissions and ED visits from Baseline to Follow-up Regardless of family income, the interactive seminar for physicians reduced hospital admissions from Follow-up 1 to Follow-up 2 and from Baseline to Final Evaluation. 3. The program effect on ED visits from Follow-up 1 to Follow-up 2 was found only in children whose family income was less than $20,000.