AVOIDABLE MORBIDITY IN INFANTS - A CLASSIFICATION BASED ON DIAGNOSES IN ADMINISTRATIVE DATABASES

OBJECTIVES. A hierarchical classification for avoidable morbidity in i nfants was developed based on a conceptual model for causes of morbidi ty. Experts rated the impact of risk factors and health services on di seases coded according to the International Classification of Diseases , 9th Revision, Classification Modification (ICD-9-CM). An etiologic f ramework was chosen for the classification because knowledge of etiolo gy often suggests strategies for prevention. Causes of morbidity that cluster on the basis of similar risk factors might be avoided using si milar strategies. METHODS. Diseases (346 different diagnoses) were rat ed by 16 general pediatricians; 12 attributes were considered, includi ng the impact on disease occurrence and on severity of five risk facto rs, preventive health services, and medical treatment. Raters evaluate d the impact of health services, constitutional risk factors, and envi ronmental risk factors without regard for service site (eg, inpatient, emergency department, primary care office). Environmental risk factor categories, including family, social, and physical environments, were rated separately. The impact of health services was rated on preventi on treatment, and complications of care. RESULTS. Only ratings indicat ing that the impact of a risk factor category was substantial were use d for the final classification of 275 diagnoses. Consistent with the m ultifactorial etiology of many diseases, many diagnoses had ratings in dicating substantial impact of multiple risk factors. Five mutually ex clusive clusters were derived from the 12 ratings based on factor anal ysis and recognized strategies for prevention. Ordered by level of avo idability, these clusters were termed vaccine-preventable, health-care quality indicators, environmental, environmental/constitutional, and constitutional. CONCLUSIONS. The usefulness of this classification for policy-oriented epidemiologic and health services research is grounde d in the premise that prevention is the cardinal objective of child he alth policy. Cluster-specific hospitalization rates, ie, rates aggrega ted for all diagnoses falling in a cluster, might be used for allocati ng resources to interventions directed at environmental or health serv ice determinants of morbidity. Widespread use of ICD-9-CM codes in hos pital discharge and ambulatory databases suggests many potential appli cations for this classification of morbidity burden in population grou ps.