Introduction: <br/>Today, significant resources are spent on accreditation in over 70 countries. Yet the <br/>documentation of the effects of accreditation on processes and outcomes of healthcare is <br/>still scarce. Thus, robust empirical studies are needed to justify the expense of time and <br/>money.<br/>Objectives:<br/>To examine the delivery of recommended patient care before and after the first-time <br/>hospital accreditation in the Faroe Islands.<br/>Hypothesis:<br/>Patients will receive more recommended patient care when treated in a hospital that has <br/>undergone accreditation.<br/>Methods:<br/>We conducted a before and after study on the Faroe Islands in connection with introducing <br/>accreditation in 2017. We compared the fulfillment of process performance measures <br/>through audit of patient records. The recommended patient care was evaluated against 67 <br/>process performance measures reflecting the national clinical guidelines. Process <br/>performance measures were calculated, as an opportunity-based composite score <br/>(percentage adherence to process performance measures) and an all-or-none score (100% <br/>adherence to process performance measures).<br/>All three hospitals participated. A random sample of patients ≥18 years, with one of seven <br/>clinical conditions (stroke/transient ischemic attack (TIA); bleeding ulcer; diabetes; chronic <br/>obstructive pulmonary disease (COPD); child birth; congestive heart failure; hip fracture) <br/>were included if they were in- or outpatients from 2012 to 2013 (before accreditation) or <br/>2017 to 2018 (after accreditation).<br/>345<br/>We calculated the relative risk, risk difference and percentage difference for receiving <br/>recommended patient care using Poisson and linear regression, respectively. In all cases, we <br/>used mixed effects analyses with a random intercept at patient and hospital level. <br/>Results:<br/>A total of 475 inpatients and 392 outpatients from the three Faroese hospitals participated. <br/>The total opportunity-based composite score, including all clinical conditions, was slightly <br/>higher after hospital accreditation (adjusted difference percentage risk (adj. diff. % risk), <br/>4.4% [95% CI -0.7;9.6]) though the increase was not statistically significant. The probability <br/>of receiving all recommended patient care was significantly higher after accreditation (total <br/>all-or-none adjusted RR, 2.32 [95% CI 2.03;2.67]).<br/>According to clinical conditions, patients with stroke/TIA (adj. diff. % risk, 17.6% [95% CI <br/>9.7;25.4]), bleeding ulcer (adj. diff. % risk, 22.5% [95% CI 18.9;26.2]), COPD (adj. diff. % risk, <br/>14.3% [95% CI 5.5;23.1]) and child birth (adj. diff. % risk, 27.9% [95% CI 24.8;31.0]) all <br/>received significantly more recommended patient care after accreditation. In contrast <br/>patients with diabetes (adj. diff. % risk, -4.3% [95% CI -6.2; -2.4]), hip fractures (adj. diff. % <br/>risk, -5.9% [95% CI -8.7; -3.1]) and heart failure (adj. diff. % risk, -1.2% [95% CI -4.2;1.7]) <br/>received less recommend patient care, however the difference was not statistically <br/>significant for heart failure.<br/>Conclusion: <br/>Hospitals were more likely to provide recommended patient care after undergoing <br/>accreditation. However, the overall improvement of process performance measures was<br/>modest. These findings provide support for the hypothesis that accreditation is associated <br/>with better health care.