Our analysis of a cohort from 6 Middle-East countries shows no increase in cumulative mortality risk (at 1-month and 1-year post admission) in patients admitted to hospitals with ACS on weekends compared with those admitted on weekdays, even after adjusting for potential confounders. Similarly, the adjusted odds ratio of mortality of patients admitted on night hours was not worse than those admitted during morning hours. A large study of patients with acute MI, from United States (n = 62,814), also could not show higher in-hospital mortality in weekend and off-hours admissions compared with those presenting during weekdays and regular hours [8
] Another study from Switzerland (n = 12,480), after adjusting for several confounding variables, could not demonstrate the “weekend effect” in patients with acute MI, and reported equal survival rates (P
= 1.00) for weekday and weekend groups [9
]. In a large Japanese registry study, there were no obvious differences in occurrence, hospital admission and acute outcome for acute MI patients in the weekday or weekend [14
]. In a study from Italy, there was an increased incidence of ST-elevation MI during weekends and night hours, which was not seen in the current study [15
In contrast, Kostis and colleagues, investigated 4 cohorts with over 230,000 patients during 1987-2002, for possible “weekend effect” [5
]. They reported 4.8% higher mortality rates at 1-month in patients admitted on weekends vs
weekdays, which persisted even after adjustment of demographic variables. The magnitude of this increase in mortality however, was reduced to 2.3% and became non-significant (P
= .09) once analysis accounted for invasive cardiac procedure. In another study in Germany, higher mortality of 1.7% remained significant despite adjustment for an array of patients’ characteristics and clinical variables [16
Studies across many disciplines quantified the “weekend effect” in terms of delays in therapeutic or diagnostic procedures and decrease in survival rates, but they failed to precisely outline the mechanisms for this effect [6
]. Most commonly, lack of staffing in terms of quantity (total number of clinical staff) and quality (senior specialist and consultants cover) appears to be commonly cited factors related to the weekend and night hours’ phenomenon [17
]. In a survey of hospitals in the United Kingdom, only 16% of hospitals provided consultant cover for 9-12 h/day for acute admissions during weekends compared with 49% during weekdays [18
]. One of the major reason for the absence of this ‘weekend effect’ could be the presence of senior level staff in the Gulf countries in terms of quantity as well as quality, as majority of the hospitals employ expatriate staff who are at senior level and experienced to work during weekends and after hours. In addition, most hospitals in the Middle-East are well-equipped with medical resources and medications, freely available at hand to provide uniform care during “out of hours” periods [19
In the present study, we found patients admitted on weekends were less likely to undergo angiography as were those admitted on weekdays. This is similar to a study from the United States of America [5
]. Quaas et al.
] found that patients in Manchester, UK, were 75% less likely to undergo coronary angiography on weekends compared with weekdays. Magid and colleagues, studied 68,439 patients with ST-segment elevation MI (STEMI) treated with fibrinolytic therapy and 33,647 treated with PCI, and reported off-hour admissions were associated with substantially longer times to treatment for PCI but not for thrombolytic therapy [2
]. Few studies report fewer PCI and significantly longer door-to-balloon time for weekends vs
]. However, in the present study, even though coronary angiography was performed less during weekends, there was no significant difference in door-to-needle as well as door-to-balloon times during weekdays and weekends. This suggests that hospital care on weekends and weekdays in the Middle-East may differ in aggressiveness, but not in quality of care. In our previous analysis, due to non-availability of catheterization facilities, the overall utilization of catheterization in ACS patients was low (at 20%) among the Gulf countries [22
] and naturally it was even lower during weekends compared with weekdays in this study.
It is also suggested that conditions with increased weekend mortality are those requiring invasive procedures [6
]. On the contrary, few authors note that the increased mortality with weekend admissions of patients with some conditions that do not require invasive therapy suggest that the increase in mortality may be due to the decreased weekend availability of cognitive skills and other hospital services rather than to fewer invasive procedures directly [23
]. In addition, in a recent Korean study which reported a higher risk of mortality on weekends vs
weekdays, medication usage was significantly low during weekends [24
]. Even though in the Middle-East overall usage of invasive procedures was low during both weekend and weekdays, we hypothesize that rest of the ACS care including recent evidence-based medication usage was similar during weekdays and weekends along with presence of senior staff leading to no difference in risk of mortality. An alternative explanation for no influence of weekend admission on mortality is that this may be an underestimate because patients admitted on weekends may ‘crossover’ to receive weekday care and vice versa as noted by others [25
Our study has several limitations. First, the number of patients who received fibrinolysis (n = 739/1718) and PCI (n = 121/1718) was small compared with all those eligible, and the impact of door-to-needle-time and door-to-balloon-time on weekend admissions could not be assessed independently of other confounders, despite both being important factors in patient survival. Secondly, 11.5 and 23% of patients were lost to follow-up at 1 month and 1 year, respectively. Patients who are lost to follow-up are likely to have died but are misclassified as lost to follow-up and thus censored in analysis rather than analyzed as an event. Although this process may underestimate mortality rates, it is unlikely to have affected weekend or weekday admission selectively and thus is unlikely to have favored weekend survival over weekdays. Thirdly, although majority of Middle-East countries employ senior expatriate physicians and nursing staff during weekends and off-hours resulting in the consistent management of ACS patients, we do not have exact information on physician characteristics (e.g. experience, specialty training) and hospital-specific characteristics (e.g. staff volume). A large number of regional hospitals in the region, however, lack on-site catheterization facilities as reported in a recent publication on ACS in the Arabian Middle East [22
]. Fourthly, the present study does not account for deaths before hospital admission which may form a significant proportion of total mortality, and thus underestimating the mortality difference. Fifth, this study did not take into account public holidays which were very few and unlikely to have affected the results. Lastly, the number of PCI and CABG procedures performed during weekends was probably too small to show any difference with weekday rates.
Future work should assess whether different characteristics at weekends play a role in influencing the risk of unstable angina. For example, different waking times, size and timing of meals, home vs work stress and increased sport activities.
In conclusion, among the Gulf States, apart from lower utilization of angiography at weekends, there were largely no significant discrepancies in the management and care of patients admitted with ACS on weekdays and during morning hours compared with patients admitted on weekends and night hours, and the overall 30-day and 1-year mortality was similar between both the cohorts. These results indicate that there is a consistent approach to the management and care of ACS patients during weekend and weekdays in the Middle-East countries.