Acute haemorrhage rate in 28,000 Out-of-Hours CT heads.

OBJECTIVES: The aim of this paper is to assess the acute haemorrhage rate in patients who had CT head investigation out-of-hours with and without trauma and compare the rates of haemorrhage between warfarin and DOACs, at a busy teritary teaching hospital. METHODS: All CT heads performed between January 2008 and December 2019 were identified from the radiology information system (RIS) at Sheffield Teaching Hospitals (STH), with the requesting information being available from January 2015. The clinical information was assessed for the mention of trauma or anticoagulation, and the reports were categorised into acute and non-acute findings. RESULTS: Between 2008 and 2019 the number of scans increased by 63%, with scans performed out of hours increasing by 278%. Between 2015 and 2019, the incidence of acute ICH was similar over the 5-year period, averaging at 6.9% and ranging from 6.1 to 7.6%. The rate of detection of acute haemorrhage following trauma was greater in those not anticoagulated (6.8%), compared with patients on anticoagulants such as warfarin (5.2%) or DOACs (2.8%). CONCLUSIONS: Over 12 years, there has been a significant increase in the number of CT heads performed at STH. The rate of ICH has remained steady over the last 5 years indicating a justified increase in imaging demand. However, the incidence of ICH in patients prescribed DOACs is lower than the general population and those on warfarin. ADVANCES IN KNOWLEDGE: This finding in a large centre should prompt discussion of the risk of bleeding with DOACs in relation to CT head imaging guidelines.

What is the demand for out-of-hours dermatology? A UK-based region-wide survey of dermatology demand and provision during the evenings and at weekends.

BACKGROUND: Little is known about the demand for out-of-hours (OOH) dermatology in the UK, and this can make commissioning of acute services difficult. The East Midlands region has a population of 4.5 million people, with variable access to OOH dermatology services. AIM: We sought to investigate the provision of, and demand for, OOH dermatology services across the region with a view to informing commissioning decisions for the future. METHODS: We contacted all dermatology departments in the East Midlands region to establish what level of service was commissioned at evenings and weekends. At the sites providing any form of OOH service, we recorded all requests for advice received after 17.00 h on weekdays, or at any time during weekends and bank holidays over a 3-month period from October to December 2019. RESULTS: The OOH services provided ranged from 24 h/day cover 7 days/week at one site, to no formal provision across much of the rest of the region. In total, 125 calls were received during the study period, averaging 1 call per day on weekday evenings, and 2 calls per day at weekends and on bank holidays. Of these 125 calls, 11 patients (9%) were prioritized and seen by the on-call dermatologist on the day of referral, and 9 of these had potentially life-threatening skin conditions. A further 39 (31%) were deemed to need review within 24 h and 22 (18%) within 48 h. The remaining 42% were given appointments within 7 days or dealt with by telephone advice. CONCLUSION: The demand for OOH dermatology across the East Midlands is low, but access to timely dermatology advice is essential in some situations. Commissioning of a regional dermatology OOH service incorporating digital technology may help to improve the equity of access for all patients across the region.

Weekend admissions with ascites are associated with delayed paracentesis: A nationwide analysis of the 'weekend effect'.

INTRODUCTION AND OBJECTIVES: Weekend admissions has previously been associated with worse outcomes in conditions requiring specialists. Our study aimed to determine in-hospital outcomes in patients with ascites admitted over the weekends versus weekdays. Time to paracentesis from admission was studied as current guidelines recommend paracentesis within 24h for all patients admitted with worsening ascites or signs and symptoms of sepsis/hepatic encephalopathy (HE). PATIENTS: We analyzed 70 million discharges from the 2005-2014 National Inpatient Sample to include all adult patients admitted non-electively for ascites, spontaneous bacterial peritonitis (SBP), and HE with ascites with cirrhosis as a secondary diagnosis. The outcomes were in-hospital mortality, complication rates, and resource utilization. Odds ratios (OR) and means were adjusted for confounders using multivariate regression analysis models. RESULTS: Out of the total 195,083 ascites/SBP/HE-related hospitalizations, 47,383 (24.2%) occurred on weekends. Weekend group had a higher number of patients on Medicare and had higher comorbidity burden. There was no difference in mortality rate, total complication rates, length of stay or total hospitalization charges between the patients admitted on the weekend or weekdays. However, patients admitted over the weekends were less likely to undergo paracentesis (OR 0.89) and paracentesis within 24h of admission (OR 0.71). The mean time to paracentesis was 2.96 days for weekend admissions vs. 2.73 days for weekday admissions. CONCLUSIONS: We observed a statistically significant "weekend effect" in the duration to undergo paracentesis in patients with ascites/SBP/HE-related hospitalizations. However, it did not affect the patient's length of stay, hospitalization charges, and in-hospital mortality.

Disparities over Time in Volume, Day of the Week, and Patient Complexity between Paracentesis and Thoracentesis Procedures Performed by Radiologists versus Those Performed by Nonradiologists.

PURPOSE: To compare the disparities between the paracenteses and thoracenteses performed by radiologists with those performed by nonradiologists over time. Variables included the volume of procedures, the days of the week, and the complexity of the patient's condition. MATERIALS AND METHODS: Using carrier claims files for a 5% national sample of Medicare beneficiaries from 2004 to 2016, paracentesis and thoracentesis examinations were retrospectively classified by physician specialty (radiologist vs nonradiologist), day of the week (weekday vs weekend), and the complexity of the patient's condition (using Charlson comorbidity index scores). The Pearson chi-square and independent samples t-test were used for statistical analysis. RESULTS: Between 2004 and 2016, the proportion of all paracentesis and thoracentesis procedures performed by radiologists increased from 70% to 80% and from 47% to 66%, respectively. Although radiologists increasingly performed more of both services on both weekends and weekdays, the share performed by radiologists was lower on weekends. For most of the first 9 years across the study period, radiologists performed paracentesis in patients with more complex conditions than those treated by nonradiologists, but the complexity of patients' conditions was similar during recent years. For thoracentesis, the complexity of patients' conditions was similar for both specialty groups across the study period. CONCLUSIONS: The proportion of paracentesis and thoracentesis procedures performed in Medicare beneficiaries by radiologists continues to increase, with radiologists increasingly performing most of both services on weekends. Nonetheless, radiologists perform disproportionately more on weekdays than on weekends. Presently, radiologists and nonradiologists perform paracentesis and thoracentesis procedures in patients with similarly complex conditions. These interspecialty differences in timing and complexity of the patient's condition differ from those recently described for several diagnostic imaging services, reflecting the unique clinical and referral patterns for invasive versus diagnostic imaging services.

Doctors' characteristics and the use of long consultations at out-of-hours services 2008-2017: a registry-based follow-up study in Norway.

Objective: The aim was to analyse whether there was a change in percentage of long consultations over a 10-year period, and whether individual doctors changed their use of time as they got more experience and specialisation during the same period. Design and setting: This is a registry based study encompassing all consultations in primary care out-of-hours service in Norway in 2008 and 2017. Subjects: For both years all doctors were included in cross sectional analyses. In addition, doctors who participated both years were included in a separate follow-up analysis. Main outcome measures: Long consultations (>20 min) were identified by a time fee in the claims' database. Results: There were 4610 doctors in 2008 and 5620 in 2017, 904 participated both years. In 2008 a time fee was claimed in 38% of consultations, in 2017 in 47%. Older doctors made less use of the time fee, as did doctors who had many consultations, regular general practitioners, and general practice specialists. The general practitioners who participated both years increased their use of the time fee from 33% to 38% of consultations. Those who specialised in general practice during the 10-year period increased their use of the time fee from 34% to 37%. Conclusions: Experienced doctors have fewer long consultations than inexperienced doctors. Over years there is a strong trend towards increasing the use of time fee during out-of-hours consultations. This trend is only partly offset by increasing the experience of the doctors. KEY POINTS Although consultation length may be associated with patient satisfaction there is also a cost-efficiency aspect to be taken into account •Percentage long consultations out-of-hours increased from 38% in 2008 to 47% in 2017 •Experienced doctors had fewer long consultations •Experience only partly offset the trend towards more long consultations.

Trends in Providing Out-of-Office, Urgent After-Hours, and On-Call Care in British Columbia.

PURPOSE: Providing care in alternative (non-office) locations and outside office hours are important elements of access and comprehensiveness of primary care. We examined the trends in and determinants of the services provided in a cohort of primary care physicians in British Columbia, Canada. METHODS: We used physician-level payments for all primary care physicians practicing in British Columbia from 2006-2007 through 2011-2012. We examined the association between physician demographics and practice characteristics and payment for care in alternative locations and after hours across rural, urban, and metropolitan areas using longitudinal mixed-effects models. RESULTS: The proportion of physicians who provided care in alternative locations and after hours declined significantly during the period, in rural, urban, and metropolitan practices. Declines ranged from 5% for long-term care facility visits to 22% for after-hours care. Female physicians, and those in the oldest age category, had lower odds of providing care at alternative locations and for urgent after-hours care. Compared with those practicing in metropolitan centers, physicians working in rural areas had significantly higher odds of providing care both in alternative locations and after hours. CONCLUSION: Care provided in non-office locations and after office hours declined significantly during the study period. Jurisdictions where providing these services are not mandated, and where similar workforce demographic shifts are occurring, may experience similar accessibility challenges.

Temporal trends and predictors of time to coronary angiography following non-ST-elevation acute coronary syndrome in the USA.

OBJECTIVE: This study aims to investigate the temporal trends in utilization of invasive coronary angiography (CA) at different time points and changing profiles of patients undergoing CA following non-ST-elevation acute coronary syndrome (NSTEACS). We also describe the association between time to CA and in-hospital clinical outcomes. PATIENTS AND METHODS: We queried the National Inpatient Sample to identify all admissions with a primary diagnosis of NSTEACS from 2004 to 2014. Patients were stratified into early (day 0, 1), intermediate (day 2) and late strategy (day≥3) according to time to CA. Multivariable logistic regression was used to investigate the association between time to CA and in-hospital mortality, major bleeding, stroke and Major Adverse Cardiac and Cerebrovascular Events. RESULTS: A total of 4 380 827 records were identified with a diagnosis of NSTEACS, out of which 57.5% received CA. The proportion of patients undergoing early CA increased from 65.6 to 72.6%, whereas late CA commensurately declined from 19.6 to 13.5%. Patients receiving early CA were younger (age: 64 vs. 70 years), more likely to be male (63.7 vs. 55.3%) and of Caucasian ethnic background (68.7 vs. 64.7%) compared with late CA group. Similarly, Women, weekend admissions and African Americans remain less likely to receive early CA. In-hospital mortality was lowest in the intermediate group (odds ratio=0.30, 95% confidence interval: 0.28-0.33). CONCLUSION: Use of early CA has increased in the management of NSTEACS; however, there remain significant disparities in utilization of an early invasive approach in women, African Americans, admission day and older patients in the USA.

Deceased Brain Dead Donor Liver Transplantation and Utilization in the United States: Nighttime and Weekend Effects.

BACKGROUND: Understanding factors that contribute to liver discards and nonusage is urgently needed to improve organ utilization. METHODS: Using Scientific Registry of Transplant Recipient data, we studied a national cohort of all US adult, deceased brain dead donor, isolated livers available for transplantation from 2003 to 2016, including organ-specific and system-wide factors that may affect organ procurement and discard rates. RESULTS: Of 73 686 available livers, 65 316 (88.64%) were recovered for transplant, of which 6454 (9.88%) were ultimately discarded. Livers that were not procured or, on recovery, discarded were more frequently from older, heavier, hepatitis B virus (HCV)+, and more comorbid donors (P < 0.001). However, even after adjustment for organ quality, the odds of liver nonusage were 11% higher on the weekend (defined as donor procurements with cross-clamping occurring from 5:00 PM Friday until 11:59 AM Sunday) compared with weekdays (P < 0.001). Nonuse rates were also higher at night (P < 0.001), defined as donor procurements with cross-clamping occurring from 5:00 PM to 5:00 AM; however, weekend nights had significantly higher nonuse rates compared with weekday nights (P = 0.005). After Share 35, weekend nonusage rates decreased from 21.77% to 19.51% but were still higher than weekday nonusage rates (P = 0.065). Weekend liver nonusage was higher in all 11 United Network of Organ Sharing regions, with an absolute average of 2.00% fewer available livers being used on the weekend compared with weekdays. CONCLUSIONS: Although unused livers frequently have unfavorable donor characteristics, there are also systemic and operational factors, including time of day and day of the week a liver becomes available, that impact the chance of liver nonprocurement and discard.

Overnight Emergency CT Imaging: A 10-Year Experience at an Irish Tertiary Referral Hospital.

In recent years there has been increased utilisation of computed tomography (CT) imaging in developed countries, however there is a paucity of data regarding the utilisation of CT in the emergency overnight setting. We retrospectively analysed trends in 'overnight' (midnight to 8am) CT utilisation over a ten-year period at a single Irish tertiary referral hospital. Over the study period, we observed a significant increase in the proportion of CT imaging that was carried out overnight. There was no significant variation in the yield of pathological findings over the study period, which remained low (64% of CT studies were normal or had non-critical findings). The multiple factors which have contributed to the increased utilization of overnight emergency CT in recent years, the potential for reporting errors overnight and the implications therein for patient safety warrant consideration.

Internal contracting of health services in Cambodia: drivers for change and lessons learned after a decade of external contracting.

BACKGROUND: Since the late 1990s, contracting has been employed in Cambodia in an attempt to accelerate rural health system recovery and improve health service delivery. Special Operating Agencies (SOA), a form of 'internal contracting', was introduced into selected districts by the Cambodia Ministry of Health in 2009. This study investigates how the SOA model was implemented and identifies effects on service delivery, challenges in operation and lessons learned. METHODS: The study was carried out in four districts, using mixed methods. Key informant interviews were conducted with representatives of donors and the Ministry of Health. In-depth interviews were carried out with managers of SOA and health facilities and health workers from referral hospitals and health centres. Data from the Annual Health Statistic Report 2009-2012 on utilisation of antenatal care, delivery and immunisation were analysed. RESULTS: There are several challenges with implementation: limited capacity and funding for monitoring the SOA, questionable reliability of the monitoring data, and some facilities face challenges in achieving the targets set in their contracts. There are some positive effects on staff behaviour which include improved punctuality, being on call for 24 h service, and perceived better quality of care, promoted through adherence to work regulations stipulated in the contracts and provision of incentives. However, flexibility in enforcing these regulations in SOA has led to more dual practice, compared to previous contracting schemes. There are reported increases in utilization of services by the general population and the poor although the quantitative findings question the extent to which these increases are attributable to the contracting model. CONCLUSION: Capacity in planning and monitoring contracts at different levels in the health system is required. Service delivery will be undermined if effective performance management is not established nor continuously applied. Improvements in the implementation of SOA include: better monitoring by the central and provincial levels; developing incentive schemes that tackle the issues of dual practice; and securing trustworthy baseline data for performance indicators.

Patient house calls in Attica and Thessaloniki, Greece (2005-2015): a model for out-of-hospital multispecialty emergency medicine.

BACKGROUND: The SOS-doctors are a network of physicians who perform house-call visits in the areas of Attica and Thessaloniki, Greece. METHODS: Patients requesting medical services by the SOS doctors during the period 1/1/2005 - 31/12/2015 were eligible for inclusion in this retrospective analysis. RESULTS: During this period 335, 212 home visits were performed. Females used this service more frequently compared to males (60.5% versus 39.5%). Among the age-groups, patients aged over 75 years made 56.6% of all house calls. Fewer phone requests were recorded during autumn than in winter (21.1% versus 29.1%). Infections were the most common cause of house-visits (29%), followed by cardiovascular diseases (10.3%), musculoskeletal (9.1%), gastrointestinal (6.3%) and neurological disorders (3.7%). An increasing demand for radiology at home was observed, starting at 352 calls in 2009 and reaching 2230 in 2015. Finally, 9.2% of patients were advised to be admitted into a hospital. CONCLUSION: A shift towards older age, but not the oldest old (> 90 years), and acute conditions was observed during the study period. The study confirms that home visits retain a significant role in the modern health care systems.

The day of the week and acute heart failure admissions: Relationship with acute myocardial infarction, 30-day readmission rate and in-hospital mortality.

BACKGROUND: In-hospital care may be constrained during the weekend due to lesser resources. Impact on outcomes of weekend versus weekday care in congestive heart failure (HF) needs further study. METHODS: Admissions with a primary diagnosis of HF using ICD-9CM codes were studied. 22,287 HF-admissions from Einstein Medical Center (2003-2013) and 2,248,482 HF-admissions from the 2002-2012 Nationwide Inpatient Sample (NIS) were analyzed separately. Primary outcomes were 30-day HF-readmission and in-hospital mortality. Logistic regression models were used to evaluate outcomes. RESULTS: Weekends experienced lower rates of admission and discharge. Mondays experienced the highest admission rate and Fridays experienced the highest discharge rate. Friday was independently associated with highest 30-day HF-readmission rates (Adjusted OR 1.12, CI 1.01-1.23; p=0.02) in addition to risk factors such as African-American race, hypertension, diabetes, hyperlipidemia, end-stage renal disease and coronary artery disease. Within the NIS sample, 85,479 in-hospital deaths (3.8%) were recorded. Compared to weekdays, patients admitted over the weekend had greater comorbidities, higher incidence of acute myocardial infarction (AMI) (15.8% vs. 16.8%; p<0.01), higher Charlson-comorbidity index and underwent less procedures such as echocardiography, right heart catheterization, coronary angiography, coronary revascularization or mechanical circulatory support. Weekend HF admission predicted higher in-hospital mortality (aOR 1.07, 95%CI 1.05-1.08; p<0.01) on multivariate analysis. This relationship was applicable for teaching and non-teaching hospitals. CONCLUSION: Friday was associated with the highest discharge and 30-day HF-readmission rate. Weekend HF admissions experienced more AMI, had greater comorbidities, received less cardiac procedures and predicted higher in-hospital mortality. Higher weekend mortality may be related to the greater degree of severity of illness among admitted patients.

Out-of-office hours' elective surgical intensive care admissions and their associated complications.

BACKGROUND: The 'weekend' effect is a controversial theory that links reduced staffing levels, staffing seniority and supportive services at hospitals during 'out-of-office hours' time periods with worsening patient outcomes. It is uncertain whether admitting elective surgery patients to intensive care units (ICU) during 'out-of-office hours' time periods mitigates this affect through higher staffing ratios and seniority. METHODS: Over a 3-year period in Western Australia's largest private hospital, this retrospective nested-cohort study compared all elective surgical patients admitted to the ICU based on whether their admission occurred 'in-office hours' (Monday-Friday 08.00-18.00 hours) or 'out-of-office hours' (all other times). The main outcomes were surgical complications using the Dindo-Clavien classification and length-of-stay data. RESULTS: Of the total 4363 ICU admissions, 3584 ICU admissions were planned following elective surgery resulting in 2515 (70.2%) in-office hours and 1069 (29.8%) out-of-office hours elective ICU surgical admissions. Out-of-office hours ICU admissions following elective surgery were associated with an increased risk of infection (P = 0.029), blood transfusion (P = 0.020), total parental nutrition (P < 0.001) and unplanned re-operations (P = 0.027). Out-of-office hours ICU admissions were also associated with an increased hospital length-of-stay, with (1.74 days longer, P < 0.0001) and without (2.8 days longer, P < 0.001) adjusting for severity of acute and chronic illnesses and inter-hospital transfers (12.3 versus 9.8%, P = 0.024). Hospital mortality (1.2 versus 0.7%, P = 0.111) was low and similar between both groups. CONCLUSION: Out-of-office hours ICU admissions following elective surgery is common and associated with serious post-operative complications culminating in significantly longer hospital length-of-stays and greater transfers with important patient and health economic implications.

Primary care services co-located with Emergency Departments across a UK region: early views on their development.

BACKGROUND: Co-location of primary care services with Emergency Departments (ED) is one initiative aiming to reduce the burden on EDs of patients attending with non-urgent problems. However, the extent to which these services are operating within or alongside EDs is not currently known.This study aimed to create a typology of co-located primary care services in operation across Yorkshire and Humber (Y&H) as well as identify early barriers and facilitators to their implementation and sustainability. METHODS: A self-report survey was sent to the lead consultant or other key contact at 17 EDs in the Y&H region to establish the extent and configuration of co-located primary care services. Semi-structured interviews were then conducted with urgent and unscheduled care stakeholders across five hospital sites to explore the barriers and facilitators to the formation and sustainability of these services. RESULTS: Thirteen EDs completed the survey and interviews were carried out with four ED consultants, one ED nurse and three general practitioners (GPs). Three distinct models were identified: 'Primary Care Services Embedded within the ED' (seven sites), 'Co-located Urgent Care Centre' (two sites) and 'GP out-of-hours' (nine sites). Qualitative data were analysed using framework analysis. Four interview themes emerged (justification for the service, level of integration, referral processes and sustainability) highlighting some of the challenges in implementing these co-located primary care services. CONCLUSION: Creating a service within or alongside the ED in which GPs can use their distinct skills and therefore add value to the existing skill mix of ED staff is an important consideration when setting up these systems. Effective triage arrangements should also be established to ensure appropriate patients are referred to GPs. Further research is required to identify the full range of models nationally and to carry out a rigorous assessment of their impact.

Differences in emergency ambulance demand between older adults living in residential aged care facilities and those living in the community in Melbourne, Australia.

OBJECTIVE: To describe the clinical presentation and temporal variation in ambulance service cases involving patients aged 65 years or older (older adults) from residential aged care facilities and those who are community dwelling (CD). METHODS: This study used four years of electronic case records from Ambulance Victoria in Melbourne, Australia. Trigonometric regression was used to analyse demand patterns. RESULTS: Residential aged care facility cases included proportionally more falls and infection-related problems and fewer circulatory-related incidents than CD cases. Community dwelling demand patterns differed between weekdays and weekends and peaked late morning. Residential aged care facility cases peaked late morning, with a secondary peak early evening, but with no significant difference between days. CONCLUSIONS: Older adult ambulance demand has distinct temporal patterns that differ by place of residence and are associated with different clinical presentations. These results provide a basis for informing ambulance planning and the identification of alternate health services.

Provision of stroke thrombolysis services in New Zealand: changes between 2011 and 2016.

AIMS: To obtain an overall picture of the organisation of stroke thrombolysis provision in New Zealand hospitals and compare changes between 2011 and 2016. METHODS: Surveys were distributed to all New Zealand district health boards (DHBs) in 2011 and 2016, and included questions about the infrastructure, staffing, training, guidelines and audit provided for stroke thrombolysis. RESULTS: Responses were received from all DHBs, with 86% offering stroke thrombolysis in 2011 and 100% in 2016. In 2016, thrombolysis rosters of large DHBs (those with a population >250,000 people) had a mean (range) of 14 (5-34) clinicians, approximately double that of medium-sized DHBs (population 125-250,000) who had eight (3-15) and small DHBs (population <125,000) with seven, (2-13) clinicians. While a similar distribution of senior medical officer clinical specialty was seen across medium and small DHBs in both years, large DHBs in 2016 had a higher number of neurologists (5, 1-12) and an increasing number of general physicians (8, 0-30) rostered to provide thrombolysis compared to 2011. Thrombolysis services at medium and small DHBs are chiefly managed by general physicians and geriatricians, while telestroke support was only available in three medium-sized DHBs. In 2016, all hospitals had developed thrombolysis guidelines and audited thrombolysed patients in the National Stroke Thrombolysis Register, which is an improvement compared with 2011 when only seven (39%) DHBs reported regular audit. Challenges in staffing and training remain greatest in smaller and geographically isolated DHBs. CONCLUSION: While there have been improvements in the provision of stroke thrombolysis throughout New Zealand, regional variations in service quality remains. The needs for better solutions to geographical barriers and formal training must be addressed as priorities.

Choice of Anesthesia for Cesarean Delivery: An Analysis of the National Anesthesia Clinical Outcomes Registry.

Neuraxial anesthesia use in cesarean deliveries (CDs) has been rising since the 1980s, whereas general anesthesia (GA) use has been declining. In this brief report we analyzed recent obstetric anesthesia practice patterns using National Anesthesiology Clinical Outcomes Registry data. Approximately 218,285 CD cases were identified between 2010 and 2015. GA was used in 5.8% of all CDs and 14.6% of emergent CDs. Higher rates of GA use were observed in CDs performed in university hospitals, after hours and on weekends, and on patients who were American Society of Anesthesiologists class III or higher and 18 years of age or younger.

Diversity and Similarity of Anesthesia Procedures in the United States During and Among Regular Work Hours, Evenings, and Weekends.

BACKGROUND: Anesthesiologists providing care during off hours (ie, weekends or holidays, or cases started during the evening or late afternoon) are more likely to care for patients at greater risk of sustaining major adverse events than when they work during regular hours (eg, Monday through Friday, from 7:00 AM to 2:59 PM). We consider the logical inconsistency of using subspecialty teams during regular hours but not during weekends or evenings. METHODS: We analyzed data from the Anesthesia Quality Institute's National Anesthesia Clinical Outcomes Registry (NACOR). Among the hospitals in the United States, we estimated the average number of common types of anesthesia procedures (ie, diversity measured as inverse of Herfindahl index), and the average difference in the number of common procedures between 2 off-hours periods (regular hours versus weekends, and regular hours versus evenings). We also used NACOR data to estimate the average similarity in the distributions of procedures between regular hours and weekends and between regular hours and evenings in US facilities. Results are reported as mean ± standard error of the mean among 399 facilities nationwide with weekend cases. RESULTS: The distributions of common procedures were moderately similar (ie, not large, <.8) between regular hours and evenings (similarity index .59 ± .01) and between regular hours and weekends (similarity index, .55 ± .02). For most facilities, the number of common procedures differed by <5 procedures between regular hours and evenings (74.4% of facilities, P < .0001) and between regular hours and weekends (64.7% of facilities, P < .0001). The average number of common procedures was 13.59 ± .12 for regular hours, 13.12 ± .13 for evenings, and 9.43 ± .13 for weekends. The pairwise differences by facility were .13 ± .07 procedures (P = .090) between regular hours and evenings and 3.37 ± .12 procedures (P < .0001) between regular hours and weekends. In contrast, the differences were -5.18 ± .12 and 7.59 ± .13, respectively, when calculated using nationally pooled data. This was because the numbers of common procedures were 32.23 ± .05, 37.41 ± .11, and 24.64 ± .12 for regular hours, evenings, and weekends, respectively (ie, >2x the number of common procedures calculated by facility). CONCLUSIONS: The numbers of procedures commonly performed at most facilities are fewer in number than those that are commonly performed nationally. Thus, decisions on anesthesia specialization should be based on quantitative analysis of local data rather than national recommendations using pooled data. By facility, the number of different procedures that take place during regular hours and off hours (diversity) is essentially the same, but there is only moderate similarity in the procedures performed. Thus, at many facilities, anesthesiologists who work principally within a single specialty during regular work hours will likely not have substantial contemporary experience with many procedures performed during off hours.