T.E.F. Abbott

Factors affecting the profitability of surgical procedures under ‘Payment by Results’

We wished to analyse the factors influencing the potential profitability of surgical operations under the National Health Service ‘Payment by Results’ scheme. First, we planned to develop a generic theoretical model describing the relationships between ‘profit’, ‘procedure duration’ and ‘costs’. Second, for a group of specific operations, we planned to investigate (using analysis of hypothetical lists) whether it was possible for hospitals to make a profit when lists were maximally efficient. ‘Efficient’ meant full utilisation of the list time, with no gaps between cases and no case cancellations. We assumed that operating theatres cost a median of £16.min−1 (range £12–20.min−1 or ∼£7680 for an 8‐h list), and we used published mean (SD) times for seven common day‐case operations (varicose veins, inguinal hernia, cataract, circumcision, hydrocoele, cystoscopy, breast biopsy). We found that even when conducted perfectly efficiently, some operations (notably varicose veins) were always unprofitable. Conversely, other operations (notably cataracts) would be likely to be profitable even if conducted inefficiently. We conclude that current tariffs do not properly reward efficiency. As tariffs are based in large part on hospitals’ reporting their own costs, flaws in the tariffs are likely to be due to inaccurate reporting. Even for this imperfect funding system, our theoretical model may help to develop strategies to maximise profit. Our analysis suggests alternative ways in which reimbursement systems could be designed to avoid creating perverse incentives and instead properly reward efficient practices.

Is 'starting on time' useful (or useless) as a surrogate measure for 'surgical theatre efficiency'?

We analysed more than 7000 theatre lists from two similar UK hospitals, to assess whether start times and finish times were correlated. We also analysed gap times (the time between patients when no anaesthesia or surgery occurs), to see whether these affected theatre efficiency. Operating list start and finish times were poorly correlated at both hospitals (r2 = 0.077 and 0.043), and cancellation rates did not increase with late starts (remaining within 2% and 10% respectively at the two hospitals). Start time did not predict finish time (receiver operating curve areas 0.517 and 0.558, respectively), and did not influence theatre efficiency (∼80–84% at either hospital). Median gap times constituted just 7% of scheduled list time and did not influence theatre efficiency below cumulative gap times of less than 15% scheduled list time. Lists with no gaps still exhibited extremely variable finish times and efficiency. We conclude that resources expended in trying to achieve prompt start times in isolation, or in reducing gap times to under ∼15% of scheduled list time, will not improve theatre productivity. Instead, the primary focus should be towards quantitative improvements in list scheduling.

Preoperative heart rate and myocardial injury after non-cardiac surgery: results of a predefined secondary analysis of the VISION study

Background Increased baseline heart rate is associated with cardiovascular risk and all-cause mortality in the general population. We hypothesized that elevated preoperative heart rate increases the risk of myocardial injury after non-cardiac surgery (MINS). Methods We performed a secondary analysis of a prospective international cohort study of patients aged ≥45 yr undergoing non-cardiac surgery. Preoperative heart rate was defined as the last measurement before induction of anaesthesia. The sample was divided into deciles by heart rate. Multivariable logistic regression models were used to determine relationships between preoperative heart rate and MINS (determined by serum troponin concentration), myocardial infarction (MI), and death within 30 days of surgery. Separate models were used to test the relationship between these outcomes and predefined binary heart rate thresholds. Results Patients with missing outcomes or heart rate data were excluded from respective analyses. Of 15 087 patients, 1197 (7.9%) sustained MINS, 454 of 16 007 patients (2.8%) sustained MI, and 315 of 16 037 patients (2.0%) died. The highest heart rate decile (>96 beats min−1) was independently associated with MINS {odds ratio (OR) 1.48 [1.23–1.77]; P<0.01}, MI (OR 1.71 [1.34–2.18]; P<0.01), and mortality (OR 3.16 [2.45–4.07]; P<0.01). The lowest decile (<60 beats min−1) was independently associated with reduced mortality (OR 0.50 [0.29–0.88]; P=0.02), but not MINS or MI. The predefined binary thresholds were also associated with MINS, but more weakly than the highest heart rate decile. Conclusions Preoperative heart rate >96 beats min−1 is associated with MINS, MI, and mortality after non-cardiac surgery. This association persists after accounting for potential confounding factors. Clinical trial registration NCT00512109.

Frequency of surgical treatment and related hospital procedures in the UK: a national ecological study using hospital episode statistics

Background Despite evidence of high activity, the number of surgical procedures performed in UK hospitals, their cost and subsequent mortality remain unclear. Methods Time-trend ecological study using hospital episode data from England, Scotland, Wales and Northern Ireland. The primary outcome was the number of in-hospital procedures, grouped using three increasingly specific categories of surgery. Secondary outcomes were all-cause mortality, length of hospital stay and healthcare costs according to standard National Health Service tariffs. Results Between April 1, 2009 and March 31, 2014, 39 631 801 surgical patient episodes were recorded. There was an annual average of 7 926 360 procedures (inclusive category), 5 104 165 procedures (intermediate category) and 1 526 421 procedures (restrictive category). This equates to 12 537, 8073 and 2414 procedures per 100 000 population per year, respectively. On average there were 85 181 deaths (1.1%) within 30 days of a procedure each year, rising to 178 040 deaths (2.3%) after 90 days. Approximately 62.8% of all procedures were day cases. Median length of stay for in-patient procedures was 1.7 (1.3-2.0) days. The total cost of surgery over the 5 yr period was £54.6 billion (

A single-centre observational cohort study of admission National Early Warning Score (NEWS).

104.4 billion), representing an average annual cost of £10.9 billion (inclusive), £9.5 billion (intermediate) and £5.6 billion (restrictive). For each category, the number of procedures increased each year, while mortality decreased. One-third of all mortalities in national death registers occurred within 90 days of a procedure (inclusive category). Conclusions The number of surgical procedures in the UK varies widely according to definition. The number of procedures is slowly increasing whilst the number of deaths is decreasing.

Measurement of Exercise Tolerance before Surgery (METS) study: a protocol for an international multicentre prospective cohort study of cardiopulmonary exercise testing prior to major non-cardiac surgery

INTRODUCTION Early warning scores are commonly used in hospitals to identify patients at risk of deterioration. The National Early Warning Score (NEWS) has recently been introduced to UK practice. However, it is not yet widely implemented. We aimed to compare NEWS to the early warning score currently used in our hospital--the Patient at Risk Score (PARS). METHODS We conducted a prospective observational cohort study of all adult general medical patients admitted to a single hospital over a 20-day period. Physiological data and early warning scores recorded in bedside charts were collected on admission and a NEWS score was retrospectively calculated. The patient notes were reviewed at 48 h after admission. The primary outcome was a composite of critical care admission or death within 2 days of admission. The secondary outcome was hospital length of stay. RESULTS NEWS was more strongly associated with the primary outcome than PARS (odds ratio 1.54, p < 0.001 compared to 1.42, p = 0.056). A NEWS of 3 or more was associated with the primary outcome (odds ratio 7.03, p = 0.003). Neither score was correlated with hospital length of stay. CONCLUSION NEWS on admission is superior to PARS for identifying patients at risk of death or critical care admission within the first 2 days of hospital stay. Current guidelines advocate a threshold of 5 for triggering a clinical review. However, since a score of 3 or more was associated with a poor outcome, this recommendation should be reviewed. Both scores were poor predictors of hospital length of stay.

A single-centre cohort study of National Early Warning Score (NEWS) and near patient testing in acute medical admissions.

Introduction Preoperative functional capacity is considered an important risk factor for cardiovascular and other complications of major non-cardiac surgery. Nonetheless, the usual approach for estimating preoperative functional capacity, namely doctors’ subjective assessment, may not accurately predict postoperative morbidity or mortality. 3 possible alternatives are cardiopulmonary exercise testing; the Duke Activity Status Index, a standardised questionnaire for estimating functional capacity; and the serum concentration of N-terminal pro-B-type natriuretic peptide (NT pro-BNP), a biomarker for heart failure and cardiac ischaemia. Methods and analysis The Measurement of Exercise Tolerance before Surgery (METS) Study is a multicentre prospective cohort study of patients undergoing major elective non-cardiac surgery at 25 participating study sites in Australia, Canada, New Zealand and the UK. We aim to recruit 1723 participants. Prior to surgery, participants undergo symptom-limited cardiopulmonary exercise testing on a cycle ergometer, complete the Duke Activity Status Index questionnaire, undergo blood sampling to measure serum NT pro-BNP concentration and have their functional capacity subjectively assessed by their responsible doctors. Participants are followed for 1 year after surgery to assess vital status, postoperative complications and general health utilities. The primary outcome is all-cause death or non-fatal myocardial infarction within 30 days after surgery, and the secondary outcome is all-cause death within 1 year after surgery. Both receiver-operating-characteristic curve methods and risk reclassification table methods will be used to compare the prognostic accuracy of preoperative subjective assessment, peak oxygen consumption during cardiopulmonary exercise testing, Duke Activity Status Index scores and serum NT pro-BNP concentration. Ethics and dissemination The METS Study has received research ethics board approval at all sites. Participant recruitment began in March 2013, and 1-year follow-up is expected to finish in 2016. Publication of the results of the METS Study is anticipated to occur in 2017.

A Prospective International Multicentre Cohort Study of Intraoperative Heart Rate and Systolic Blood Pressure and Myocardial Injury After Noncardiac Surgery: Results of the VISION Study

INTRODUCTION The utility of an early warning score may be improved when used with near patient testing. However, this has not yet been investigated for National Early Warning Score (NEWS). We hypothesised that the combination of NEWS and blood gas variables (lactate, glucose or base-excess) was more strongly associated with clinical outcome compared to NEWS alone. METHODS This was a prospective cohort study of adult medical admissions to a single-centre over 20days. Blood gas results and physiological observations were recorded at admission. NEWS was calculated retrospectively and combined with the biomarkers in multivariable logistic regression models. The primary outcome was a composite of mortality or critical care escalation within 2days of hospital admission. The secondary outcome was hospital length of stay. RESULTS After accounting for missing data, 15 patients out of 322 (4.7%) died or were escalated to the critical care unit. The median length of stay was 4 (IQR 7) days. When combined with lactate or base excess, NEWS was associated with the primary outcome (OR 1.18, p=0.01 and OR 1.13, p=0.03). However, NEWS alone was more strongly associated with the primary outcome measure (OR 1.46, p<0.01). The combination of NEWS with glucose was not associated with the primary outcome. Neither NEWS nor any combination of NEWS and a biomarker were associated with hospital length of stay. CONCLUSION Admission NEWS is more strongly associated with death or critical care unit admission within 2days of hospital admission, compared to combinations of NEWS and blood-gas derived biomarkers.

A systematic review and consensus definitions for standardised end-points in perioperative medicine: pulmonary complications

BACKGROUND: The association between intraoperative cardiovascular changes and perioperative myocardial injury has chiefly focused on hypotension during noncardiac surgery. However, the relative influence of blood pressure and heart rate (HR) remains unclear. We investigated both individual and codependent relationships among intraoperative HR, systolic blood pressure (SBP), and myocardial injury after noncardiac surgery (MINS). METHODS: Secondary analysis of the Vascular Events in Noncardiac Surgery Cohort Evaluation (VISION) study, a prospective international cohort study of noncardiac surgical patients. Multivariable logistic regression analysis tested for associations between intraoperative HR and/or SBP and MINS, defined by an elevated serum troponin T adjudicated as due to an ischemic etiology, within 30 days after surgery. Predefined thresholds for intraoperative HR and SBP were: maximum HR >100 beats or minimum HR <55 beats per minute (bpm); maximum SBP >160 mm Hg or minimum SBP <100 mm Hg. Secondary outcomes were myocardial infarction and mortality within 30 days after surgery. RESULTS: After excluding missing data, 1197 of 15,109 patients (7.9%) sustained MINS, 454 of 16,031 (2.8%) sustained myocardial infarction, and 315 of 16,061 patients (2.0%) died within 30 days after surgery. Maximum intraoperative HR >100 bpm was associated with MINS (odds ratio [OR], 1.27 [1.07–1.50]; P < .01), myocardial infarction (OR, 1.34 [1.05–1.70]; P = .02), and mortality (OR, 2.65 [2.06–3.41]; P < .01). Minimum SBP <100 mm Hg was associated with MINS (OR, 1.21 [1.05–1.39]; P = .01) and mortality (OR, 1.81 [1.39–2.37]; P < .01), but not myocardial infarction (OR, 1.21 [0.98–1.49]; P = .07). Maximum SBP >160 mm Hg was associated with MINS (OR, 1.16 [1.01–1.34]; P = .04) and myocardial infarction (OR, 1.34 [1.09–1.64]; P = .01) but, paradoxically, reduced mortality (OR, 0.76 [0.58–0.99]; P = .04). Minimum HR <55 bpm was associated with reduced MINS (OR, 0.70 [0.59–0.82]; P < .01), myocardial infarction (OR, 0.75 [0.58–0.97]; P = .03), and mortality (OR, 0.58 [0.41–0.81]; P < .01). Minimum SBP <100 mm Hg with maximum HR >100 bpm was more strongly associated with MINS (OR, 1.42 [1.15–1.76]; P < .01) compared with minimum SBP <100 mm Hg alone (OR, 1.20 [1.03–1.40]; P = .02). CONCLUSIONS: Intraoperative tachycardia and hypotension are associated with MINS. Further interventional research targeting HR/blood pressure is needed to define the optimum strategy to reduce MINS.

Arterial pulse pressure and postoperative morbidity in high-risk surgical patients

Background: There is a need for robust, clearly defined, patient‐relevant outcome measures for use in randomised trials in perioperative medicine. Our objective was to establish standard outcome measures for postoperative pulmonary complications research. Methods: A systematic literature search was conducted using MEDLINE, Web of Science, SciELO, and the Korean Journal Database. Definitions were extracted from included manuscripts. We then conducted a three‐stage Delphi consensus process to select the optimal outcome measures in terms of methodological quality and overall suitability for perioperative trials. Results: From 2358 records, the full texts of 81 manuscripts were retrieved, of which 45 met the inclusion criteria. We identified three main categories of outcome measure specific to perioperative pulmonary outcomes: (i) composite outcome measures of multiple pulmonary outcomes (27 definitions); (ii) pneumonia (12 definitions); and (iii) respiratory failure (six definitions). These were rated by the group according to suitability for routine use. The majority of definitions were given a low score, and many were imprecise, difficult to apply consistently, or both, in large patient populations. A small number of highly rated definitions were identified as appropriate for widespread use. The group then recommended four outcome measures for future use, including one new definition. Conclusions: A large number of postoperative pulmonary outcome measures have been used, but most are poorly defined. Our four recommended outcome measures include a new definition of postoperative pulmonary complications, incorporating an assessment of severity. These definitions will meet the needs of most clinical effectiveness trials of treatments to improve postoperative pulmonary outcomes.