The Royal College of Physicians stroke programme has been carrying out systematic audits of the quality of stroke care across England, Wales, and Northern Ireland since 1998. These audits have focused mainly on process measures of quality (e.g. access to thrombolysis). The validity of this methodology assumes that these measures are a useful proxy of subsequent outcomes; however there is currently only limited evidence for this.
The purpose of this study therefore was to estimate the relation between individual process measures for the quality of acute stroke care (the assessments, interventions, and treatments that patients receive) with 30-day all-cause mortality using observational data collected through two national clinical audits - the Stroke Improvement National Audit Programme (SINAP) and the National Sentinel Stroke Audit.
106 hospitals participating in these two audits admitted a total of 36,197 adults with acute ischaemic stroke during the study period (April 2010 to November 2011). Process of care was measured using the following six individual measures of stroke care and summarised into an overall quality score:
• Seen by a stroke consultant or associate specialist within 24 hours of admission
• Brain scan within 24 hours of admission
• Bundle 1: seen by nurse and one therapist within 24 hours and all relevant therapists within 72 hours
• Bundle 2: nutrition screening and formal swallow assessment within 72 hours where appropriate
• Bundle 3: patient’s first ward of admission was stroke unit and they arrived there within four hours of hospital admission
• Bundle 4: patient given antiplatelet therapy where appropriate and had adequate fluid and nutrition for first 72 hours
Process measures used in the SINAP that applied to fewer than 80% of patients (including thrombolysis if eligible) were not considered.
The authors report that three of the individual processes were associated with reduced mortality. The strongest association was seen for bundle 4: patient given antiplatelet therapy where appropriate and adequate fluid and nutrition for first 72 hours (adjusted odds ratio of death of 0.46 [95% CI 0.42 to 0.50; p<0.0001]; multivariable analysis, excluding death or palliative care in first 3 days). Receipt of five or six care processes was associated with lower mortality compared with receipt of 0-4 in both multilevel (0.74, 0.66 to 0.83) and instrumental variable analyses (0.62, 0.46 to 0.83). Patients admitted to stroke services with high organisational scores were more likely to receive most (5 or 6) of the six care processes.
The authors discuss the limitations of their study, including the lack of data on outcomes other than mortality (not available in the SINAP dataset), the reliance on data supplied by hospitals participating in voluntary audit, and the lack of information on the National Institutes of Health stroke severity score measure.
Based on their results, the authors suggest that further controlled trials of the measured individual care bundles are warranted. They say that their results have important implications for quality improvement in stroke services and also contribute more generally to the evidence base for quality measures in healthcare.