Hospital accreditation programs can be defined as the systematic assessment of hospitals against accepted standards. These initiatives have been frequently adopted worldwide to assess and improve healthcare service quality. The process is conducted by independent bodies, external to the hospital structure, usually comprising nongovernmental and nonprofit organizations. It includes staff training, establishing a team project, selecting standards to be followed, and implementing specified requirements. It also comprises survey visits by a multidisciplinary healthcare team, leading to a detailed report of identified areas of improvement and the next cycle of follow-up visits. It is, therefore, a process that demands time and money from hospital institutions that is carried out with the expectation of ensuring the efficient use of resources invested and generating improvements in healthcare quality.
However, some factors raise doubts about the benefits achieved with hospital accreditation. Results are often not immediate and are difficult to measure, as it is not easy to isolate variables and attribute the improvements achieved solely to obtaining accreditation. In addition, the path is dynamic and can evolve from an initial state without certification to different stages of accreditation, nationally and internationally, impacting the efficiency and quality of hospitals along this journey.
In light of a non-consensual picture of the impacts of hospital accreditation and the scarcity of systematic analyses on this topic, the study performed by  sought to investigate what the scientific evidence tells us about the mensurable impact of hospital accreditation on healthcare quality dimensions.
The impact of hospital accreditation was assessed considering healthcare quality indicators across seven dimensions, acknowledged by the World Health Organization, Avedis Donabedian, and the Institute of Medicine: safety, efficiency, effectiveness, patient focus, equity, access, and timeliness. The study was based on a systematic review of the literature in eight international databases, initially identifying 943 articles dealing with the topic. Only 36 of them were selected for further analysis, as they objectively verified the impact generated by accreditation, comparing quality indicators before and after the accreditation process, or indicators of accredited hospitals in comparison to non-accredited hospitals.
The analyzed articles reported a positive impact of accreditation in three dimensions: patient safety, efficiency, and effectiveness. In the patient safety dimension, the improvements related to the adoption of evidence-based care, and lower rates of infection, adverse events, and incidents of bedsores. Concerning efficiency, lower staff turnover, more complete medical records, improved processes of documentation by nurses, better facilities and physical infrastructure, greater professional satisfaction, and better waste management were observed. Finally, in the case of effectiveness, the improvements associated with the accreditation were a lower length of stay, mortality rate, and readmission rates.
These results reinforce some positive aspects of accreditation, such as the adoption of preestablished explicit standards to guide the processes of care, the establishment of management systems, and the standardization of procedures and internal policies (8,10). When the accreditation takes into consideration well-established metrics of healthcare quality, such as medication errors, it can contribute to improvements in the related domain of patient safety.
Regarding to a healthcare focused on the patient, only seven of the 36 articles investigated indicators related to this domain, and the results were mixed. Four articles reported no impact from accreditation, while three concluded that there was a positive impact on satisfaction and respect for patients' rights and privacy. The findings of the seven articles allow a relevant insight. Improving processes (efficiency dimension) and, consequently, increasing the resolution and safety of procedures (effectiveness and patient safety dimensions) does not necessarily translate into quality as perceived by patients (patient-centeredness domain).
The access and timeliness dimensions were also the subject of very few studies, and the results showed null impact. Finally, no article was found focusing on the effect of accreditation on the equity of health services delivered to the population. Therefore, there is a knowledge gap to be tapped in further studies on the impact of hospital accreditation specifically related to these domains. These dimensions comprise important challenges affecting the population, especially the most vulnerable groups, and health sector managers in virtually all health systems. Issues related to long waiting times, non-availability, or inequitable distribution of health services also contribute to the exponential increase in the judicialization of health.
More recently , took a similar approach to systematically review quantitative studies measuring the impact of hospital accreditation, grouped in six outcome categories: organizational culture and management, professionals-reported outcomes, patient-reported outcomes, patient clinical outcomes, economic and performance measures. In line with the main conclusions of , despite mixed results for some outcome categories, and the methodological issues to be considered, a positive accreditation effect was found in the majority of the 76 analyzed studies. A consistent positive effect of accreditation was observed for process-related performance indicators, safety culture, hospital efficiency, and patient length of stay. In contrast, staff job stress was found to be consistently negatively affected, staff job satisfaction, patient satisfaction and experience, and 30-day readmission rate were found to be unrelated to accreditation, and heterogenous results were observed for mortality and healthcare-associated infection.
In general terms, the results indicate that the accreditation process has the potential to generate improvements in important indicators of hospital quality, benefiting the institution and patients. However, the results should be interpreted with caution, in light of the methodological limitations of the analyzed studies. The studies investigated different accreditation programs (with specificities that may have impacted the observed results) and different hospital types (concerning the number of beds, specialties, the country, and the overall environment where the hospital is based). Furthermore, isolating the effect of accreditation on the observed results is a major challenge, and it is not possible to exclude the possibility of uncontrolled factors confounding the results.
For studies that compared the results of accredited versus non-accredited hospitals is also unclear whether the better results observed in accredited hospitals are related to changes brought by the accreditation itself, or whether a hospital that voluntarily undergoes an accreditation process tends to reveal an institution that is already more motivated and prepared to comply with the guidelines and obtain the certificate of this type of program. In scenarios where accreditation is a choice rather than an obligation, there is a possibility that hospitals with better and more resources are more prone to go through this process, as to confirm their excellence.
Likewise, the comparison of the quality indicators pre- and post- accreditation has some limitations, not being possible to affirm that variations in results are exclusively attributable to the impact of accreditation. The longer the study, the greater the chance that unanticipated elements will interfere with the results. Given that accreditation often aims a process of continuous improvement, it is difficult to define the ideal assessment periods (of hospital quality indicators) before and after the intervention (accreditation). In turn, if the assessment takes place right before and after the accreditation, it may not capture the medium and long-term sustainability of results, considering that the efforts and improvements brought by the accreditation may dissipate once the evaluation process is finished and the certificate is obtained. The same methodological issues were pointed by .
Thus, some important question remains: does accreditation improve quality indicators, or do better quality indicators result in the institution's accreditation? How long does the return on investment take? Are the results sustainable in the long-term? That is, how long does it take for institutions to start reaping the rewards of this process? What organizational and contextual aspects can mediate the impacts of accreditation on quality indicators, hampering or facilitating the expected results? For now, the positive impact of accreditation on hospital quality indicators has a component of faith, but with good indications that, in general, it is worth investing in this process.