Case Fatality of Stroke and Day of the Week: Is the Weekend Effect an Artifact?

Abstract

Background and Purpose: For stroke admissions, the ‘weekend effect’ has been associated with higher stroke fatality. However, it is unclear if stroke case fatality shows this pattern if the onset day is taken into account. Day of the week variation in stroke case fatality was examined using 16-year stroke registration data. Design and Methods: Data were obtained from Takashima Stroke Registry in central Japan. There were 1,578 registered first-ever cerebral infarction and cerebral hemorrhage stroke cases during 1988–2003. We divided the days into 2 groups: ‘weekend’ and ‘weekdays’. The 7-day and 28-day case fatality rates and 95% confidence intervals (95% CI) were calculated by gender, age and stroke subtype. Results: For all strokes, the 7-day case fatality rate based on the hospital admission day was 9.5% (95% CI: 6.8–13.1) for weekend admissions and 7.3% (95% CI: 6.0–8.9) for weekday admissions. However, case fatality rates based on the onset day were 7.2% (95% CI: 5.1–10.0) for weekend onset and 8.0% (95% CI: 6.6–9.8) for weekday onset. The 28-day case fatality rate for the weekend admission group was 14.7% (95% CI: 11.3–18.8) and for the weekday admission group it was 10.1% (95% CI: 8.5–11.9). In contrast, the 28-day case fatality rate for the weekend onset group was 11.3% (95% CI: 8.6–14.7) and for the weekday onset group it was 11.0% (95% CI: 9.3–13.0). This phenomenon was observed mainly for cerebral infarction and to some extent for cerebral hemorrhage. Conclusion: Stroke fatality rates based on the day of admission were higher during the weekend than weekdays, although the difference did not reach statistical significance. However, this trend disappeared when the fatality rate was based on the day of onset.

Effect of Weekend Compared With Weekday Stroke Admission on Thrombolytic Use, In-Hospital Mortality, Discharge Disposition, Hospital Charges, and Length of Stay in the Nationwide Inpatient Sample Database, 2002 to 2007

“…15 Our study eliminated this artifact by only including emergency room admissions and excluding hospital transfers.…”

“…8 We only included emergency room admissions for stroke to eliminate the artifact from patients transferred from other hospitals on days other than their day of admission that was found in the Takashima Stroke Registry study. 15 We chose to only study ischemic stroke, because there have been previous studies using the NIS database to analyze a weekend effect on intracerebral hemorrhage 16 and subarachnoid hemorrhage. 17 Interestingly, in this present study, we found that weekend patients with stroke were slightly more likely to receive thrombolytics but there was no difference in in-hospital mortality, which is similar to the findings from the Virginia Patient Data System.…”

Stroke Case Fatality Shows Seasonal Variation Regardless of Risk Factor Status in a Japanese Population: 15-Year Results from the Takashima Stroke Registry

“…This was the reason we chose to use the 7-day case fatality indicator [21] to analyze the impact of season on fatality. We also used the conventional method of identifying case fatality, the 28-day case fatality [16] .…”

Within-Day and Weekly Variations of Thrombolysis in Acute Ischemic Stroke

“…19,20 Some authors argued that the weekend effect might be an artifact because the tendency toward a higher weekend fatality disappeared when stroke onset time, and not hospital admission time, was taken into account by eliminating the bias of the potential exclusion of nonfatal cases having deferred admission. 41 Finally, other studies, some of which specifically focused on patients treated with thrombolysis, did not observe a night or weekend effect. [25][26][27][28][29] All those studies were conducted in single or few centers in a single country and hence were at risk for center effects, and their results could not be generalized.…”