The authors of J. A. Casey et al [Reference Casey, Cosgrove, Stewart, Pollak and Schwartz1] have discovered an error in the programming used in the analysis for their article.

In the original article 3970 MRSA cases were identified from Geisinger Health System's electronic health record. The error led to the inclusion of 17 cases without a MRSA infection and the exclusion of 49 cases with a MRSA infection from 2001–2010. Five HA-MRSA and 9 CA-MRSA cases were incorrectly included in the analysis, and 18 HA-MRSA and 30 CA-MRSA cases were incorrectly excluded.

The corrected numbers are 4002 MRSA cases, with 1734 CA and 1519 HA-MRSA. Most changes were in 2008 (12 cases removed, 10 added) and 2009 (2 cases removed, 26 cases added). The corrected CA and HA-MRSA incidence rates from 2005–2009 per 100,000 person-years are: 69·5, 135·1, 143·5, 168·2, 204·3 and 111·5, 136·5, 118·0, 142·6, and 134·1, respectively. The mean annual incidence rate, mean percent increase in MRSA incidence, and annual average percent increase in CA-MRSA remain unchanged. The mean annual percent increase in HA-MRSA is now 6% (range −15 to 51%).

The error did not lead to any substantive changes in Tables 1–4 or in the paper's other results or conclusions.

The corrected tables can be found online at supplementary online material http://dx.doi.org/10.1017/S0950268812003081