Limits...
“ Weekend effect ” on stroke mortality revisited

View Article: PubMed Central - PubMed

ABSTRACT

Previous studies have yielded inconsistent results on whether weekend admission is associated with increased mortality after stroke, partly because of differences in case mix. Claims-based studies generally lack sufficient information on disease severity and, thus, suffer from inadequate case-mix adjustment. In this study, we examined the effect of weekend admission on 30-day mortality in patients with ischemic stroke by using a claims-based stroke severity index.

This was an observational study using a representative sample of the National Health Insurance claims data linked to the National Death Registry. We identified patients hospitalized for ischemic stroke, and examined the effect of weekend admission on 30-day mortality with vs without adjustment for stroke severity by using multilevel logistic regression analysis adjusting for patient-, physician-, and hospital-related factors. We analyzed 46,007 ischemic stroke admissions, in which weekend admissions accounted for 23.0%. Patients admitted on weekends had significantly higher 30-day mortality (4.9% vs 4.0%, P < 0.001) and stroke severity index (7.8 vs 7.4, P < 0.001) than those admitted on weekdays. In multivariate analysis without adjustment for stroke severity, weekend admission was associated with increased 30-day mortality (odds ratio (OR), 1.20; 95% confidence interval [CI], 1.08–1.34). This association became after adjustment for stroke severity (OR, 1.07; 95% CI, 0.95–1.20).

The “weekend effect” on stroke mortality might be attributed to higher stroke severity in weekend patients. While claims data are useful for examining stroke outcomes, adequate adjustment for stroke severity is warranted.

No MeSH data available.


Related in: MedlinePlus

Number of admissions, mean stroke severity index, and 30-day mortality according to day of the week. The dashed line in the lower panel indicates the mean of admissions per day.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4998342&req=5

Figure 1: Number of admissions, mean stroke severity index, and 30-day mortality according to day of the week. The dashed line in the lower panel indicates the mean of admissions per day.

Mentions: Even though the SSI correlates well with stroke severity,[18] some concerns are raised because the SSI is not specific for evaluation of stroke severity and could be affected by complications of stroke. Actually, the rationale behind the development of the SSI lies in the observation that a higher stroke severity leads to more complications.[18] The component items of the SSI reflect how these complications are treated and, consequently, a higher SSI value stands for a more severe stroke. It may be argued that poor care quality also results in complications, and thus increases the value of SSI. The high SSI on weekends might be due to low care quality during this period. However, if this is the case, then it is hard to explain the result of the lowest SSI on Monday (Fig. 1) because it is unlikely that patients admitted on Monday received a better quality of care than those admitted from Tuesday through Friday. Therefore, we believe that the high SSI on weekends truly represents high stroke severity although we are unable to rule out the possibility that care quality might play a minor role.


“ Weekend effect ” on stroke mortality revisited
Number of admissions, mean stroke severity index, and 30-day mortality according to day of the week. The dashed line in the lower panel indicates the mean of admissions per day.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4998342&req=5

Figure 1: Number of admissions, mean stroke severity index, and 30-day mortality according to day of the week. The dashed line in the lower panel indicates the mean of admissions per day.
Mentions: Even though the SSI correlates well with stroke severity,[18] some concerns are raised because the SSI is not specific for evaluation of stroke severity and could be affected by complications of stroke. Actually, the rationale behind the development of the SSI lies in the observation that a higher stroke severity leads to more complications.[18] The component items of the SSI reflect how these complications are treated and, consequently, a higher SSI value stands for a more severe stroke. It may be argued that poor care quality also results in complications, and thus increases the value of SSI. The high SSI on weekends might be due to low care quality during this period. However, if this is the case, then it is hard to explain the result of the lowest SSI on Monday (Fig. 1) because it is unlikely that patients admitted on Monday received a better quality of care than those admitted from Tuesday through Friday. Therefore, we believe that the high SSI on weekends truly represents high stroke severity although we are unable to rule out the possibility that care quality might play a minor role.

View Article: PubMed Central - PubMed

ABSTRACT

Previous studies have yielded inconsistent results on whether weekend admission is associated with increased mortality after stroke, partly because of differences in case mix. Claims-based studies generally lack sufficient information on disease severity and, thus, suffer from inadequate case-mix adjustment. In this study, we examined the effect of weekend admission on 30-day mortality in patients with ischemic stroke by using a claims-based stroke severity index.

This was an observational study using a representative sample of the National Health Insurance claims data linked to the National Death Registry. We identified patients hospitalized for ischemic stroke, and examined the effect of weekend admission on 30-day mortality with vs without adjustment for stroke severity by using multilevel logistic regression analysis adjusting for patient-, physician-, and hospital-related factors. We analyzed 46,007 ischemic stroke admissions, in which weekend admissions accounted for 23.0%. Patients admitted on weekends had significantly higher 30-day mortality (4.9% vs 4.0%, P < 0.001) and stroke severity index (7.8 vs 7.4, P < 0.001) than those admitted on weekdays. In multivariate analysis without adjustment for stroke severity, weekend admission was associated with increased 30-day mortality (odds ratio (OR), 1.20; 95% confidence interval [CI], 1.08–1.34). This association became after adjustment for stroke severity (OR, 1.07; 95% CI, 0.95–1.20).

The “weekend effect” on stroke mortality might be attributed to higher stroke severity in weekend patients. While claims data are useful for examining stroke outcomes, adequate adjustment for stroke severity is warranted.

No MeSH data available.


Related in: MedlinePlus