The weekend factor: the effect on healthcare quality. A medico-legal, retrospective study.

Background: In the healthcare system, in the last 30 years, the prognostically negative value of the so-called Weekend Effect (WE) has been internationally recognized. The WE is regarded as the increased risk a patient might incur when hospitalized during non-working days, of enduring severe complications in comparison to the same hospitalization that occur on working days. The aim of this study was to retrospectively verify whether, once a mistake was made during weekends or on holidays, in comparison to a mistake occurred on workdays, it subsequently implied a higher risk of complications, death included, in a statistical and medico-legal way.

Methods: Three different evaluators independently examined a total of 378 medico-legal cases over a more than 20-year period. Eventual medical actions and omissions were labelled as 'mistake' when the AJ claimed that at least one occurred; 'alleged mistake' included the cases where the EW's report disagreed with the AJ's one; finally, 'no mistake' when both the AJ and the EW agreed in their evaluations. During weekends there is a higher risk that a mistake occurs (OR=3.3, 95% CI=1.6;7.4; p-value<0.001) compared to weekdays. When death occurs, delayed diagnosis is the main cause (p=0.02), whereas a damaging action is more frequently claimed in general.

Conclusions: We verified as actual the impact of the WE on patients' outcome from a medico-legal point of view. The implications for an improvement of the several settings of the Italian NHS are various, and many are the consequences in the healthcare management.