<p><strong>OBJECTIVES: </strong>To use adherence to the Pediatric Respiratory Illness Measurement System (PRIMES) indicators to evaluate the strength of associations for individual indicators with length of stay (LOS) and cost for bronchiolitis.</p>

<p><strong>METHODS: </strong>We prospectively enrolled children with bronchiolitis at 5 children's hospitals between July 1, 2014, and June 30, 2016. We examined associations between adherence to each individual PRIMES indicator for bronchiolitis and LOS and cost. Sixteen indicators were included, 9 "overuse" indicators for care that should not occur and 7 "underuse" indicators for care that should occur. We performed mixed effects linear regression to examine the association between adherence to each individual indicator and LOS (hours) and cost (dollars). All models controlled for patient demographics, patient complexity, and hospital.</p>

<p><strong>RESULTS: </strong>We enrolled 699 participants. The mean age was 8 months; 56% were male, 38% were white, and 63% had public insurance. Three indicators were significantly associated with shorter LOS and lower cost. All 3 indicators were overuse indicators and related to laboratory testing: no blood cultures (adjusted mean difference in LOS: -24.3 hours; adjusted mean cost difference: -$731, &lt; .001), no complete blood cell counts (LOS: -17.8 hours; cost: -$399, &lt; .05), and no respiratory syncytial virus testing (LOS: -16.6 hours; cost: -$272, &lt; .05). Two underuse indicators were associated with higher cost: documentation of oral intake at discharge ($671, &lt; .01) and documentation of hospital follow-up ($538, &lt; .05).</p>

<p><strong>CONCLUSIONS: </strong>A subset of PRIMES quality indicators for bronchiolitis are strongly associated with improved outcomes and can serve as important measures for future quality improvement efforts.</p>