Prescribing Patterns and Retreatment Rates in Patients With Otitis Media

T.I. Shireman and K.A. Kelsey

Clin Drug Invest. 2002;22(5) 

In This Article


Demographic data for the study population and the eligible Ohio Medicaid population are displayed in Table 1 . Among 80 133 continuously eligible children, there were 9177 cases of new-onset acute OM, with an incidence rate of 11.5%. The proportion of females among nonsuppurative, suppurative and all cases was similar to the eligible population. The mean age of children diagnosed with OMwas 2.8 years, compared with a mean age of 3.6 years in the eligible Ohio Medicaid paediatric cohort (recipients aged 3 months to 7 years). OM occurred with the greatest frequency among 1-year olds, accounting for 22.4% of cases. Frequency of OM decreased as age increased. Among incident cases, Caucasians were more commonly diagnosed than African-Americans. Caucasians accounted for approximately 85% of cases compared with 77.1% of the eligible population. In contrast, fewer African-Americans were represented among the incident cases (12.2%) compared with their proportion among the eligibles (19.6%). The proportion of cases for Hispanics and other races were consistent with the eligible population.

Regarding concurrent infections, 14.1% had a concurrent diagnosis of an URI and 6.3% had a concurrent diagnosis of chronic OM (data not in table). The majority of OM cases were coded as suppurative (65.6%) [ Table 1 ], and suppurative cases were more likely to involve younger (t = 3.3, p = 0.001), Caucasian (Chi-square = 36.6, p < 0.001) children.

Empiric treatment choices for nonsuppurative and suppurative cases are shown in figure 1. More cases of suppurative OM (42.9%) received amoxicillin compared with the nonsuppurative group (35.0%), but there were fewer suppurative cases who did not receive any antibiotic (untreated, 18.0%) compared with the nonsuppurative group (31.0%). Other treatment choices were fairly consistent across the two types of diagnoses with the biggest difference being in the use of amoxicillin/clavulanic acid.

Overall retreatment rates were higher for suppurative than nonsuppurative diagnoses (29.3 versus 26.2%, respectively). Nonsuppurative cases had retreatment rates that ranged from 16.4% (erythromycin/first generation cephalosporins group) to 36.2% (amoxicillin/clavulanic acid) [figure 2]. Twenty-seven percent of those not empirically treated with an antibiotic (untreated) initially received an antibiotic between days 3 and 30 after the initial visit. Among children with suppurative diagnoses, retreatment rates ranged from 25% (amoxicillin) to 35.1% (second and third generation cephalosporins). Retreatment rates for five of the seven groups (six antibiotic groups and the no-treatment group) were higher for the suppurative cases than for the nonsuppurative cases.

Prescriber characteristics were identifiable in 81% (n = 5786) of the empirically treated cases. Paediatricians and general practitioners/internal medicine physicians accounted for the majority of cases (45 and 37.4%, respectively), whereas emergency physicians treated 5.1% of cases. The remaining 13% of cases were treated by other specialties.

The first logistic regression analysis was the prediction of the probability of receiving an antibiotic ( Table 2 ). Children who had a diagnosis of chronic OM were less likely to receive an antibiotic [Adjusted Odds Ratio (AOR) = 0.61; 95% confidence interval (CI) = 0.51, 0.74]. African-American children were more likely to receive an antibiotic (AOR = 1.22; 95% CI = 1.04, 1.43) than Caucasian children, and children with a suppurative diagnosis (AOR = 2.02; 95% CI = 1.83, 2.24) and those with a concurrent URI (AOR = 1.59; 95% CI = 1.36, 1.86) were also more likely to receive an antibiotic.

The next model examined factors predicting the likelihood, among those empirically treated, of receiving amoxicillin as the first antibiotic ( Table 2 ). African-American (AOR = 1.69; 95% CI = 1.46, 1.95) and Hispanic children (AOR = 1.50; 95% CI = 1.04, 2.18) were more likely to receive amoxicillin than Caucasian children. General practitioners and internal medicine physicians were slightly less likely to prescribe amoxicillin than paediatricians (AOR = 0.90; 95% CI = 0.81, 1.00), but the difference between other physician specialties and paediatricians was much greater (AOR ≤ 0.58; 95% CI = 0.49, 0.68). Children with a chronic OM diagnosis were less likely to receive amoxicillin (AOR = 0.68; 95% CI = 0.55, 0.85), as were children with a concurrent URI (AOR = 0.81; 95% CI = 0.71, 0.93).

Finally, we examined the factors that influenced the likelihood of receiving retreatment ( Table 2 ). Retreatment rates declined with age (AOR = 0.91; 95% CI = 0.89, 0.93) and were lower for African-Americans (AOR = 0.71; 95% CI = 0.61, 0.83). Children who received a sulfa drug/sulfa combination or amoxicillin were also less likely to receive retreatment (AOR= 0.78; 95% CI = 0.64, 0.95; and AOR = 0.70; 95% CI = 0.62, 0.79, respectively) than those who were untreated initially. Those diagnosed with a suppurative infection were slightly more likely to receive retreatment (AOR = 1.17; 95% CI = 1.06, 1.29).