Of the 1458 youth and parents in the initial sample, 170 were ineligible leaving an eligible sample of 1288. Reasons for ineligibility included: child did not have asthma (n=63), disenrolled from GHC (n=84), language ineligibility (n=11), parent too ill (n=6) and other (n=6). Of the eligible sample, 833 parents gave consent and permission for the study to contact their child with asthma. From these 833, the study obtained child consent and completed 781 interviews for a final recruitment rate of 60.6%. The final sample that this analysis will be based on is 769 youth (12 youth or their parent did not give permission for the use of cost and utilization data). Full details of the sample are published elsewhere 19
Sample characteristics, costs and utilization
The demographic and health characteristics of the total sample are described in . The 2006 HEDIS definition classified 518 (67%) as high-risk, whereas the revised definition classified only 223 (29%) as high-risk. All youth classified as high-risk by the revised definition were also classified as high-risk by the 2006 HEDIS definition. The total health care costs and utilization related to asthma of the total sample are described in . For the total sample (N=769) total health care costs were $2,759 in Year 1 and $2,503 in Year 2.
Patient characteristics and asthma related function of total sample and risk groups
Health care cost and utilization for total sample and risk groups
Criterion and step-wise comparison of high-risk definitions
reports the number of youth identified by each individual criterion. The definitions were also examined in a step-wise manner and the cumulative number of youth identified with each additional criterion is reported for each definition. Nine youth (1.2%) had inpatient hospitalizations, and 65 youth (8.5%) had inpatient hospitalizations or emergency department visits. The addition of the revised definition criterion ‘one or more prescriptions for oral steroids’ identified a total of 223 youth (29.0%). In contrast, the addition of the HEDIS criterion ‘four or more prescriptions for asthma’ identifies a total of 514 youth (66.8%) and the fourth HEDIS criterion ‘four or more ambulatory visits and two or more prescriptions for asthma’ captures an additional four youth, for a total of 518 (67.4%). The 2006 HEDIS definition identified 295 youth as high-risk that the revised definition did not identify; these 295 youth had no asthma-related hospitalizations, emergency department visits, or prescriptions for oral steroids.
Number of youth captured by high-risk definition criteria (N=769)
Demographic and health characteristics by risk group
The 2006 HEDIS definition identified a high-risk group that was very similar to the 2006 HEDIS definition low-risk group in demographic and health plan characteristics (). In contrast, the revised definition identified a high-risk group that was older and had lower parental educational attainment compared to the low-risk group. Both definitions identified high-risk groups with greater morbidity compared to the respective low-risk groups. The high-risk group for either definition had higher mean Pediatric Chronic Disease Scores, had been diagnosed with asthma approximately one year earlier, had more days of asthma symptoms in the prior two weeks and slightly lower CHS-A emotional health scores than the low-risk group. There were no differences between groups in the CHS-A activity limitation scores.
The only statistically significant difference between the two high-risk groups was in self-reported asthma-related physical limitations, indicated by the CHS-A physical health score, which was worse for the revised definition high-risk group compared to the 2006 HEDIS definition high-risk group. The revised definition high-risk group reported more symptom days than the HEDIS definition high-risk group, but this difference was not statistically significant.
Cost and utilization of health services by risk group
Cost and utilization of health services for each group, in years one and two, are presented in and described below.
2006 HEDIS definition high-risk versus low-risk youth
There was no difference in Year 1 total health services costs between the 2006 HEDIS high-risk and low-risk groups, however Year 2 total health services costs were higher for the high-risk group than the low-risk group. Utilization of all types (inpatient hospitalizations for asthma, emergency department and ambulatory visits for asthma, and for prescriptions for asthma medication) in both Year 1 and Year 2 was higher for the 2006 HEDIS definition high-risk group than the low-risk group.
Revised definition high-risk versus low-risk youth
Total health services costs in both Year 1 and Year 2 were higher for the revised definition high-risk group compared to the low-risk group. The high-risk group had higher utilization of all types in Year 1 and also higher utilization of all types in Year 2 except for inpatient hospitalizations compared to the low-risk group.
Comparison of high-risk youth according to the two definitions
The revised definition high-risk group had higher Year 1 total health services costs than the 2006 HEDIS high-risk group. Year 2 total health services costs, were $600 higher for the revised definition high-risk group compared to the 2006 HEDIS definition high-risk group but were not statistically different. Youth in the revised definition high-risk group made more emergency department visits and outpatient visits, and were more likely to have used any oral steroids for asthma in Year 1, compared to the 2006 HEDIS definition high-risk group. In Year 2, youth in the revised definition high-risk group made more emergency department visits and were more likely to have used any oral steroids for asthma compared to the 2006 HEDIS definition high-risk group.