Childhood Asthma Control and Community Pharmacies: Moving to Population Health

Background

Childhood asthma morbidity varies tremendously across regions.  Pharmacies are well-positioned for an increased role in population health management.  We hypothesized that the asthma medication ratio (AMR), a nationally-recognized patient-level quality metric, could be calculated at the pharmacy-level (Ph-AMR) and would be associated with community morbidity.

Methods

We examined asthma medication fills for children (0-18 years) between 1/31/2010-1/30/2012 at 29 retail pharmacies in a single chain within Greater Cincinnati.  Medications were categorized “controller” (inhaled corticosteroids, leukotriene receptor antagonists) or “rescue” (inhaled beta-agonists).  Ph-AMR was calculated by dividing controller by controller+rescue fills, similar to the patient-level AMR where ratios <0.5 are associated with increased morbidity.  Community asthma morbidity was defined as utilization (emergency department visitation or hospitalization) rates in the census tracts where the pharmacies were located.  Associations between Ph-AMR and community morbidity were assessed using linear regression.

 

Results

There were 41,307 asthma medications filled; the average Ph-AMR was 0.52 (range 0.38-0.66).  Pharmacies’ census tracts had average annual rates of 30.2 utilizations per 1,000 children (range 2.3-65.8).  Low Ph-AMR (<0.5) pharmacies were in census tracts with utilization rates significantly greater than high Ph-AMR (≥0.5) pharmacies (46.9 vs. 15.2 per 1,000; p=0.0008).  Ph-AMR accounted for 52% of utilization rate variation (p<0.0001).  For every 0.1 increase in Ph-AMR, the utilization rate decreased by 12.8 per 1,000 (p=0.004), after adjustment for census tract poverty and transportation access.

 

Conclusions

The Ph-AMR was strongly and independently associated with local childhood asthma morbidity.  Pharmacies may be a population health leverage point for assessing and improving asthma control within a community.