Elsevier

The Lancet

Volume 388, Issue 10040, 9–15 July 2016, Pages 170-177
The Lancet

Articles
Weekly variation in health-care quality by day and time of admission: a nationwide, registry-based, prospective cohort study of acute stroke care

https://doi.org/10.1016/S0140-6736(16)30443-3Get rights and content

Summary

Background

Studies in many health systems have shown evidence of poorer quality health care for patients admitted on weekends or overnight than for those admitted during the week (the so-called weekend effect). We postulated that variation in quality was dependent on not only day, but also time, of admission, and aimed to describe the pattern and magnitude of variation in the quality of acute stroke care across the entire week.

Methods

We did this nationwide, registry-based, prospective cohort study using data from the Sentinel Stroke National Audit Programme. We included all adult patients (aged >16 years) admitted to hospital with acute stroke (ischaemic or primary intracerebral haemorrhage) in England and Wales between April 1, 2013, and March 31, 2014. Our outcome measure was 30 day post-admission survival. We estimated adjusted odds ratios for 13 indicators of acute stroke-care quality by fitting multilevel multivariable regression models across 42 4-h time periods per week.

Findings

The study cohort comprised 74 307 patients with acute stroke admitted to 199 hospitals. Care quality varied across the entire week, not only between weekends and weekdays, with different quality measures showing different patterns and magnitudes of temporal variation. We identified four patterns of variation: a diurnal pattern (thrombolysis, brain scan within 12 h, brain scan within 1 h, dysphagia screening), a day of the week pattern (stroke physician assessment, nurse assessment, physiotherapy, occupational therapy, and assessment of communication and swallowing by a speech and language therapist), an off-hours pattern (door-to-needle time for thrombolysis), and a flow pattern whereby quality changed sequentially across days (stroke-unit admission within 4 h). The largest magnitude of variation was for door-to-needle time within 60 min (range in quality 35–66% [16/46–232/350]; coefficient of variation 18·2). There was no difference in 30 day survival between weekends and weekdays (adjusted odds ratio 1·03, 95% CI 0·95–1·13), but patients admitted overnight on weekdays had lower odds of survival (0·90, 0·82–0·99).

Interpretation

The weekend effect is a simplification, and just one of several patterns of weekly variation occurring in the quality of stroke care. Weekly variation should be further investigated in other health-care settings, and quality improvement should focus on reducing temporal variation in quality and not only the weekend effect.

Funding

None.

Introduction

The quality of health care that patients receive might be partly determined by when they are admitted to hospital.1 The weekend effect (ie, poorer care quality and outcomes for patients admitted at the weekend than for those admitted during the week) or the off-hour effect (poorer care of patients admitted outside of usual working hours than of those admitted during regular hours) have been reported in many studies across a wide variety of clinical presentations.2, 3, 4 Such studies have had a major, and sometimes contentious, effect on health policy—eg, by prompting moves to increase the number of doctors working in hospitals at weekends.5 However, evidence for why health-care quality might be worse overnight or at the weekend is scarce and any understanding remains largely speculative,6 creating difficulty in health-policy development and quality improvement. Moreover, previous studies have generally compared weekdays with weekends, or regular hours with off-hours, rather than measuring care quality across both day of the week and time. This approach risks obscuring other patterns of temporal variation in care quality, which might have important implications for understanding and improving the quality of health-care services.

We therefore aimed to describe the pattern and magnitude of weekly variation in several domains of care quality for people admitted to hospital with acute stroke. Globally, stroke is the second leading cause of death7 and the third largest contributor to disease burden.8 There is good quality evidence for acute interventions (such as intravenous thrombolysis with alteplase and organised stroke-unit care) improving outcomes after stroke;9 how quickly acute stroke care is delivered is therefore both important and can be measured against evidence-based standards. We postulated that care quality is dependent not only on day of admission, but also time of admission.

Research in context

Evidence before this study

Between Jan 1, 1980, and May 31, 2015, we searched MEDLINE for English-language studies published before June, 2015, investigating temporal variation in health-care quality. Our main focus was to identify studies of stroke care, but we also searched for studies done in other clinical settings. Our search terms were “Weekend”, “Weekend effect”, “Off hours”, “Temporal variation”, “AND Stroke”, “AND quality”. Studies of the weekend effect were identified in a wide range of clinical settings and geographical locations, describing evidence of poorer outcomes for patients admitted on the weekend or overnight with myocardial infarction, stroke, and general emergency admissions. We identified only a few studies that examined variation across both time of admission and day of week, including a study of obstetric outcomes in California, USA, and a study of hospital inpatients from Australia.

Added value of this study

Our study shows that in acute stroke care, the weekend effect is just one of several patterns of variation in quality that occur in real-world practice. Quality varied across the whole week, and different aspects of quality showed different patterns of variation.

Implications of all the available evidence

These findings imply that in acute stroke care, the weekend effect is a simplification of the true extent of temporal variation in health-care quality that occurs across the week. A focus only on reducing differences in care quality between weekends and weekdays will therefore not fully address the problem of variation in health-care quality across the week. Although we only examined care quality in the stroke setting, findings from previous studies assessing the weekend effect in a wide variety of clinical settings suggest that weekly variations in quality might also be pervasive across acute health-care settings. Such variations should be sought for and be a focus of quality improvement efforts.

Section snippets

Study design and patients

We did this nationwide, registry-based, prospective cohort study using data from the Sentinel Stroke National Audit Programme (SSNAP)—the national register of stroke care in England and Wales. SSNAP collects data for the clinical characteristics and care quality (measuring various aspects of care from the time of admission up to 6 months after stroke) of patients admitted to all acute-care hospitals in England and Wales with acute ischaemic stroke or primary intracerebral haemorrhage. Data were

Statistical analysis

Our outcome measure was 30 day post-admission survival. We did time-stratified analyses by classifying patients according to time of admission. We used time of stroke onset for patients who had stroke while in hospital. We used two methods for stratifying time. First, we used six, 4 h time blocks per day of the week (0000 h to 0359 h, 0400 h to 0759 h, 0800 h to 1159 h, 1200 h to 1559 h, 1600 h to 1959 h, and 2000 h to 2359 h), resulting in 42 time categories in total. We chose 4 h periods

Results

The study cohort comprised 74 307 patients with acute stroke admitted to 199 hospitals. The median age of patients was 77 years (IQR 67–85) and 65 193 (88%) patients had an ischaemic stroke (table 1). The most frequent day of admission was Monday, and admissions were less frequent on Saturdays and Sundays than on weekdays (table 1). Discharges from hospital were less common at weekends than during the week (table 1). Data were 100% complete for all baseline variables apart from NIHSS on

Discussion

Our study shows that variations in the quality of acute stroke care happen across the whole week and not only between weekends and weekdays, with individual indicators of care quality differing in the magnitude and pattern of variation. This finding suggests that even within a single, well-defined clinical pathway such as acute stroke care, temporal variation is a complex occurrence that probably has various causes. Our findings show that the concept of the weekend effect is a major

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