Prophylaxis of topical levofloxacin against endophthalmitis after cataract surgery in Taiwan, 2001-2019: an interrupted time series analysis.

Background: Since May 2007, topical levofloxacin 0.5% ophthalmic solution for prophylaxis of postoperative endophthalmitis (POE) in cataract surgery has been reimbursable in Taiwan.

Aim: We used the National Health Insurance Research Database to estimate the practice of levofloxacin in cataract surgery from 2001 to 2019 and compared the POE rates before and after the introduction of levofloxacin using interrupted time series (ITS) analysis.

Method: We did propensity score-based stabilized weights (PSSW) for each quarterly cohort and used the Joinpoint Regression Program to determine the significant change time point.

Results: 1,456,380 patients and 2,208,126 eyes were eligible. The Joinpoint Regression Program revealed a significant change in the second quarter of 2010. Levofloxacin use started from 0% in the second quarter of 2007, and increased to 6.3% and 30.2% in the second quarter of 2010 and the last quarter of 2019. The POE rate (per 1000 eyes) was 3.7 in the first quarter of 2001, reduced to 1.9, 1.7, and 1.4 in the first, second quarters of 2010, and the last quarter of 2019, respectively. ITS reveals a significant but smaller time trend of - 0.0088‰ during 2010Q2-2019 (post-interruption). The r-square between the levofloxacin use and the POE rate was 0.305. The results of ITS and r-square after PSSW are similar to those without PSSW.

Conclusion: Although the POE reduction rate in cataract surgery aligns with the increased use of levofloxacin, the small r-square and low usage implied topical levofloxacin use is not the sole determinant of POE reduction.