Preventive therapy for asthmatic children under Florida Medicaid: changes during the 1990s

In response to the increasing prevalence and severity of asthma in this country, the National Institutes of Health in 1991 published an expert consensus report Guidelines for the Diagnosis and Management of Asthma. An important aspect of the report included the recommendation that children with moderate asthma may benefit from daily treatment with anti-inflammatory drugs such as inhaled corticosteroids and cromolyn.

The objective of this article is to examine changes in prescribing of daily anti-inflammatory drugs for children covered by Florida Medicaid during two 2-year periods, the first just after publication of the Guidelines and the second 7 years later; and to estimate adherence to treatment by children who received one of them.

The study groups for each of the two 2-year periods included only children 2 to 18 years old who had medical or institutional claims to Medicaid for asthma and who were continuously covered during the period. From outpatient claims files, a record was assembled for each child containing the number of prescriptions in each category of asthma drugs during each interval. For each child who had received a prescription for any daily preventative drug, the number of such prescriptions and the time after the first were used to calculate availability of medication.

The proportion of children receiving at least one prescription for a preventive drug rose from 26.9 per cent of children in 1990-1992 to 52.6 per cent in 1997-1998. African-American children were less likely to receive a preventive in the earlier period, but the difference narrowed by 1997. Assuming that one refill provided a month's supply of drug, the percentage of children who had enough drug dispensed to treat for more than half of the time following the initial prescription rose from 6.1 to 11.2 per cent. For children with the highest use of beta-agonist (11 or more prescriptions over 2 years), the percentage rose from 25.3 to 35.8; in those with 5 or more courses of a systemic steroid, the proportion rose from 36.6 to 40.2. During the second interval, adherence to use of oral montelukast was no better than to inhaled daily medications.

In the 7 years after the publication of the NIH Guidelines, asthmatic children covered by Florida Medicaid had an approximate doubling in the proportion who received a prescription for a daily anti-inflammatory drug. However, during both intervals the adherence to treatment once prescribed remained low even among those with the severest asthma. Effective strategies to improve adherence will be needed before these drugs can realize their potential.