OBJECTIVES: To compare healthcare resource utilization (HRU) in patients with conjunctivitis ("cases") versus those without conjunctivitis ("controls") in the general population (GP) and in those with prior antibiotic-resistant infection (ARI).

METHODS: Optum Healthcare Solutions data (1/1/1998-6/30/2016) were used. GP cases had ≥1 diagnosis claim for any conjunctivitis type (index date defined as first claim), and ≥60 days of continuous enrolment before ("baseline period") and after index date. A 60-day washout period (no conjunctivitis/related medication claims) preceded the index date. GP controls never had a conjunctivitis claim; index date was randomly assigned based on distribution of time between enrolment and index date in GP cases. ARI cases were selected like GP cases but had ≥1 ARI diagnosis within 180 days before first conjunctivitis diagnosis. Index date for ARI controls was based on time between ARI diagnosis and index date in ARI cases. All-cause HRU over 60 days post-index date was compared between cases and controls using Poisson incidence rate ratios (IRR). Inverse probability of treatment weights were used to adjust for baseline differences.

RESULTS: After weighting, baseline differences between cases and controls were well-balanced (GP cases n=1,002,188, controls n=4,877,210; ARI cases n=706, controls n=15,368). Mean age (years) in GP cases and controls was 39.3 and 38.0, respectively; 46.6% and 47.7% were male. Among ARI cases and controls, mean age was 53.4 and 51.1, respectively; 47.5% and 50.2% were male. HRU was higher in cases in both cohorts: all visits (GP: IRR= 2.12 [95% CI: 2.12-2.13]; ARI: 1.41 [1.23-1.63]), hospitalizations (GP: 1.66 [1.62-1.71]; ARI: 1.54 [1.16-2.03]), emergency room visits (GP: 3.10 [3.08-3.13]; ARI: 1.90 [1.37-2.63]), and outpatient visits (GP: 2.18 [2.17-2.18]; ARI: 1.35 [1.21-1.52]). GP cases also incurred more hospitalization days (1.46 [1.42-1.50]).

CONCLUSIONS: Conjunctivitis is associated with increased HRU in both GP and ARI patients. Research on cost implications is warranted.