Ambulatory Cardiology or General Internal Medicine Assessment Prior to Scheduled Major Vascular Surgery is Associated with Improved Outcomes.

OBJECTIVE: To characterize the association between ambulatory cardiology or general internal medicine (GIM) assessment prior to surgery and outcomes following scheduled major vascular surgery. BACKGROUND: Cardiovascular risk assessment and management prior to high-risk surgery remains an evolving area of care. METHODS: This is population-based retrospective cohort study of all adults who underwent scheduled major vascular surgery in Ontario, Canada, April 1, 2004-March 31, 2019. Patients who had an ambulatory cardiology and/or GIM assessment within 6 months prior to surgery were compared to those who did not. The primary outcome was 30-day mortality. Secondary outcomes included: composite of 30-day mortality, myocardial infarction or stroke; 30-day cardiovascular death; 1-year mortality; composite of 1-year mortality, myocardial infarction or stroke; and 1-year cardiovascular death. Cox proportional hazard regression using inverse probability of treatment weighting (IPTW) was used to mitigate confounding by indication. RESULTS: Among 50,228 patients, 20,484 (40.8%) underwent an ambulatory assessment prior to surgery: 11,074 (54.1%) with cardiology, 8,071 (39.4%) with GIM and 1,339 (6.5%) with both. Compared to patients who did not, those who underwent an assessment had a higher Revised Cardiac Risk Index (N with Index over 2= 4,989[24.4%] vs. 4,587[15.4%], P<0.001) and more frequent pre-operative cardiac testing (N=7,772[37.9%] vs. 6,113[20.6%], P<0.001) but, lower 30-day mortality (N=551[2.7%] vs. 970[3.3%], P<0.001). After application of IPTW, cardiology or GIM assessment prior to surgery remained associated with a lower 30-day mortality (weighted Hazard Ratio [95%CI] = 0.73 [0.65-0.82]) and a lower rate of all secondary outcomes. CONCLUSIONS: Major vascular surgery patients assessed by a cardiology or GIM physician prior to surgery have better outcomes than those who are not. Further research is needed to better understand potential mechanisms of benefit.

Cystatin C or creatinine for pre-operative assessment of kidney function and risk of post-operative acute kidney injury: a secondary analysis of the METS cohort study.

Background: Post-operative acute kidney injury (PO-AKI) is a common surgical complication consistently associated with subsequent morbidity and mortality. Prior kidney dysfunction is a major risk factor for PO-AKI, however it is unclear whether serum creatinine, the conventional kidney function marker, is optimal in this population. Serum cystatin C is a kidney function marker less affected by body composition and might provide better prognostic information in surgical patients. Methods: This was a pre-defined, secondary analysis of a multi-centre prospective cohort study of pre-operative functional capacity. Participants were aged ≥40 years, undergoing non-cardiac surgery. We assessed the association of pre-operative estimated glomerular filtration rate (eGFR) calculated using both serum creatinine and serum cystatin C with PO-AKI within 3 days after surgery, defined by KDIGO creatinine changes. The adjusted analysis accounted for established AKI risk factors. Results: A total of 1347 participants were included (median age 65 years, interquartile range 56-71), of whom 775 (58%) were male. A total of 82/1347 (6%) patients developed PO-AKI. These patients were older, had higher prevalence of cardiovascular disease and related medication, were more likely to have intra-abdominal procedures, had more intraoperative transfusion, and were more likely to be dead at 1 year after surgery 6/82 (7.3%) vs 33/1265 (2.7%) (P = .038). Pre-operative eGFR was lower in AKI than non-AKI patients using both creatinine and cystatin C. When both measurements were considered in a single age- and sex-adjusted model, eGFR-Cysc was strongly associated with PO-AKI, with increasing risk of AKI as eGFR-Cysc decreased below 90, while eGFR-Cr was no longer significantly associated. Conclusions: Data from over 1000 prospectively recruited surgical patients confirms pre-operative kidney function as major risk factor for PO-AKI. Of the kidney function markers available, compared with creatinine, cystatin C had greater strength of association with PO-AKI and merits further assessment in pre-operative assessment of surgical risk.

Association between preoperative cardiac risk assessment and health care costs in major noncardiac surgery: a multicentre health economic analysis.

PURPOSE: Patients with impaired functional capacity who undergo major surgery are at increased risk of postoperative morbidity including complications and increased length of stay. These outcomes have been associated with increased hospital and health system costs. We aimed to assess whether common preoperative risk indices are associated with postoperative cost. METHODS: We conducted a health economic analysis focused on the subset of Measurement of Exercise Tolerance before Surgery (METS) study participants in Ontario, Canada. Participants were scheduled for major elective noncardiac surgery and underwent several preoperative assessments of cardiac risk, including physicians' subjective assessment, Duke Activity Status Index (DASI) questionnaire, peak oxygen consumption, and N-terminal pro-B-type natriuretic peptide concentration. Using linked health administrative data, postoperative costs were calculated for both one year and in-hospital. Using multiple regression models, we tested for association between the preoperative measures of cardiac risk and postoperative costs. RESULTS: Our study included 487 patients (mean [standard deviation] age 68 [11] yr and 47.0% female) who underwent noncardiac surgery between 13 June 2013 and 8 March 2016. Overall, the median [interquartile range] cost incurred within one year postoperatively was CAD 27,587 [13,902-32,590], of which CAD 12,928 [10,253-12,810] were incurred in-hospital and CAD 14,497 [10,917-15,017] were incurred by 30 days. None of the four preoperative measures of cardiac risk assessment were associated with costs incurred in hospital or at one year postoperatively. This lack of strong association persisted in sensitivity analyses considering type of surgical procedure, burden of preoperative cost, and when costs were categorized as quantiles. CONCLUSION: In patients undergoing major noncardiac surgery, common measures of functional capacity are not consistently associated with total postoperative cost. Until further data exist that differ from this analysis, clinicians and health care funders should not assume that preoperative measures of cardiac risk are associated with annual health care or hospital costs for such surgeries.

RéSUMé: OBJECTIF: La patientèle présentant une capacité fonctionnelle dégradée qui bénéficie d'une intervention chirurgicale majeure court un risque accru de morbidité postopératoire, y compris de complications et de prolongation de la durée de séjour. Ces issues ont été associées à une augmentation des coûts hospitaliers et du système de santé. Notre objectif était d'évaluer si des indices de risque préopératoires communs étaient associés aux coûts postopératoires. MéTHODE: Nous avons effectué une analyse de l'économie de la santé axée sur le sous-ensemble des participant·es à l'étude METS (Measurement of Exercise Tolerance before Surgery) en Ontario, au Canada. Les participant·es devaient bénéficier d'une chirurgie non cardiaque et non urgente majeure et ont complété plusieurs évaluations préopératoires du risque cardiaque, notamment l'évaluation subjective des médecins, le questionnaire DASI (Duke Activity Status Index), la consommation maximale d'oxygène et la concentration de prohormone N-terminale du peptide natriurétique de type B (cérébral) (NT-proBNP). À l'aide de données administratives couplées de santé, les coûts postopératoires ont été calculés à la fois pour une année et à l'hôpital. À l'aide de modèles de régression multiples, nous avons testé l'association entre les mesures préopératoires du risque cardiaque et les coûts postopératoires. RéSULTATS: Notre étude a inclus 487 personnes (âge moyen [écart type] 68 [11] ans et 47,0 % de femmes) ayant bénéficié d'une chirurgie non cardiaque entre le 13 juin 2013 et le 8 mars 2016. Dans l'ensemble, le coût médian [écart interquartile] engagé dans l'année qui a suivi l'opération était de 27 587 CAD [13 902­32 590], dont 12 928 CAD [10 253­12 810] ont été encourus à l'hôpital et 14 497 CAD [10 917­15 017] ont été encourus dans les premiers 30 jours. Aucune des quatre mesures préopératoires de l'évaluation du risque cardiaque n'était associée aux coûts engagés à l'hôpital ou un an après l'opération. Cette absence d'association forte persistait dans les analyses de sensibilité tenant compte du type d'intervention chirurgicale, du fardeau des coûts préopératoires et lorsque les coûts étaient classés en quantiles. CONCLUSION: Chez la patientèle bénéficiant d'une chirurgie non cardiaque majeure, les mesures courantes de la capacité fonctionnelle ne sont pas systématiquement associées au coût postopératoire total. Jusqu'à ce qu'il existe d'autres données qui diffèrent de cette analyse, les cliniciens et cliniciennes et les organismes finançant les soins de santé ne devraient pas présumer que les mesures préopératoires du risque cardiaque sont associées aux coûts annuels des soins de santé ou des hôpitaux pour de telles chirurgies.

Assessment of the incremental prognostic value from the modified frailty index-5 in complete traumatic cervical spinal cord injury.

Frailty, as measured by the modified frailty index-5 (mFI-5), and older age are associated with increased mortality in the setting of spinal cord injury (SCI). However, there is limited evidence demonstrating an incremental prognostic value derived from patient mFI-5. We conducted a retrospective cohort study to evaluate in-hospital mortality among adult complete cervical SCI patients at participating centers of the Trauma Quality Improvement Program from 2010 to 2018. Logistic regression was used to model in-hospital mortality, and the area under the receiver operating characteristic curve (AUROC) of regression models with age, mFI-5, or age with mFI-5 was used to compare the prognostic value of each model. 4733 patients were eligible. We found that both age (80 y versus 60 y: OR 3.59 95% CI [2.82 4.56], P < 0.001) and mFI-5 (score ≥ 2 versus < 2: OR 1.53 95% CI [1.19 1.97], P < 0.001) had statistically significant associations with in-hospital mortality. There was no significant difference in the AUROC of a model including age and mFI-5 when compared to a model including age without mFI-5 (95% CI Δ AUROC [- 8.72 × 10-4 0.82], P = 0.199). Both models were superior to a model including mFI-5 without age (95% CI Δ AUROC [0.06 0.09], P < 0.001). Our findings suggest that mFI-5 provides minimal incremental prognostic value over age with respect to in-hospital mortality for patients complete cervical SCI.

Survival and health care costs after inpatient elective surgery: comparison of patients with and without chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is common among surgical patients, and patients with COPD have higher risk for complications and death within 30 days after surgery. We sought to describe the longer-term postoperative survival and costs of patients with COPD compared with those without COPD within 1 year after inpatient elective surgery. METHODS: In this retrospective population-based cohort study, we used linked health administrative databases to identify all patients undergoing inpatient elective surgery in Ontario, Canada, from 2005 to 2019. We ascertained COPD status using validated definitions. We followed participants for 1 year after surgery to evaluate survival and costs to the health system. We quantified the association of COPD with survival (Cox proportional hazards models) and costs (linear regression model with log-transformed costs) with partial adjustment (for sociodemographic factors and procedure type) and full adjustment (also adjusting for comorbidities). We assessed for effect modification by frailty, cancer and procedure type. RESULTS: We included 932 616 patients, of whom 170 482 (18%) had COPD. With respect to association with risk of death, COPD had a partially adjusted hazard ratio (HR) of 1.61 (95% confidence interval [CI] 1.58-1.64), and a fully adjusted HR of 1.26 (95% CI 1.24-1.29). With respect to impact on health system costs, COPD was associated with a partially adjusted relative increase of 13.1% (95% CI 12.7%-13.4%), and an increase of 4.6% (95% CI 4.3%-5.0%) with full adjustment. Frailty, cancer and procedure type (such as orthopedic and lower abdominal surgery) modified the association between COPD and outcomes. INTERPRETATION: Patients with COPD have decreased survival and increased costs in the year after surgery. Frailty, cancer and the type of surgical procedure modified associations between COPD and outcomes, and must be considered when risk-stratifying surgical patients with COPD.

Measurement properties of the WHO Disability Assessment Schedule 2.0 for evaluating functional status after inpatient surgery.

BACKGROUND: Expert recommendations propose the WHO Disability Assessment Schedule (WHODAS) 2.0 as a core outcome measure in surgical studies, yet data on its long-term measurement properties remain limited. These were evaluated in a secondary analysis of the Measurement of Exercise Tolerance before Surgery (METS) prospective cohort. METHODS: Participants were adults (40 years of age or older) who underwent inpatient non-cardiac surgery. The 12-item WHODAS and EQ-5DTM-3L questionnaires were administered preoperatively (in person) and 1 year postoperatively (by telephone). Responsiveness was characterized using standardized response means (SRMs) and correlation coefficients between change scores. Construct validity was evaluated using correlation coefficients between 1-year scores and comparisons of WHODAS scores across clinically relevant subgroups. RESULTS: The analysis included 546 patients. There was moderate correlation between changes in WHODAS and various EQ-5DTM subscales. The strongest correlation was between changes in WHODAS and changes in the functional domains of the EQ-5D-3L-for example, mobility (Spearman's rho 0.40, 95 per cent confidence interval [c.i.] 0.32 to 0.48) and usual activities (rho 0.45, 95 per cent c.i. 0.30 to 0.52). When compared across quartiles of EQ-5D index change, median WHODAS scores followed expected patterns of change. In subgroups with expected functional status changes, the WHODAS SRMs ranged from 'small' to 'large' in the expected directions of change. At 1 year, the WHODAS demonstrated convergence with the EQ-5D-3L functional domains, and good discrimination between patients with expected differences in functional status. CONCLUSION: The WHODAS questionnaire has construct validity and responsiveness as a measure of functional status at 1 year after major surgery.

Surgery can have a long-lasting impact on a person's 'functional status', which is their ability to carry out routine functions of daily living (e.g. work, chores, and social activity). International societies now recommend that functional status be routinely measured in research studies of patients having surgery. A potential instrument to measure functional status in patients having surgery is the WHO Disability Assessment Schedule (WHODAS) 2.0. The WHODAS 2.0 was originally designed to measure function and disability in a general population (i.e. not patients having surgery). In this study, we show that the WHODAS 2.0 has acceptable performance when measuring functional status in patients having surgery.

Frailty assessment tools for use by surgeons when evaluating older adults prior to surgery: a scoping review protocol.

INTRODUCTION: Despite growing evidence, uncertainty persists about which frailty assessment tools are best suited for routine perioperative care. We aim to understand which frailty assessment tools perform well and are feasible to implement. METHODS AND ANALYSIS: Using a registered protocol following Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA), we will conduct a scoping review informed by the Joanna Briggs Institute Guide for Scoping Reviews and reported using PRISMA extension for Scoping Reviews recommendations. We will develop a comprehensive search strategy with information specialists using the Peer Review of Electronic Search Strategies checklist, and implement this across relevant databases from 2005 to 13 October 2021 and updated prior to final review publication. We will include all studies evaluating a frailty assessment tool preoperatively in patients 65 years or older undergoing intracavitary, non-cardiac surgery. We will exclude tools not assessed in clinical practice, or using laboratory or radiologic values alone. After pilot testing, two reviewers will independently assess information sources for eligibility first by titles and abstracts, then by full-text review. Two reviewers will independently chart data from included full texts using a piloted standardised electronic data charting. In this scoping review process, we will (1) index frailty assessment tools evaluated in the preoperative clinical setting; (2) describe the level of investigation supporting each tool; (3) describe useability of each tool and (4) describe direct comparisons between tools. The results will inform ready application of frailty assessment tools in routine clinical practice by surgeons and other perioperative clinicians. ETHICS AND DISSEMINATION: Ethic approval is not required for this secondary data analysis. This scoping review will be published in a peer-review journal. Results will be used to inform an ongoing implementation study focused on geriatric surgery to overcome the current lack of uptake of older adult-oriented care recommendations and ensure broad impact of research findings.

Perioperative risk assessment - focus on functional capacity.

PURPOSE OF REVIEW: This review examines how functional capacity informs preoperative risk stratification, as well as strengths and limitations of options for estimating functional capacity. RECENT FINDINGS: Functional capacity (or cardiopulmonary fitness) overlaps with other important characteristics, including muscular strength, balance, and frailty. Poor functional capacity is associated with postoperative morbidity, especially noncardiovascular complications. Both patient interviews and exercise tests are used to assess functional capacity. The usual approach of an unstructured patient interview does not predict outcomes. Structured interviews that incorporate validated questionnaires (Duke Activity Status Index) or standardized questions about physical activity (ability to climb stairs) do predict moderate-or-severe complications and cardiovascular complications. Among exercise tests, cardiopulmonary exercise testing (CPET) has shown the most consistent association with risks of complications. Other tests (6-min walk test, incremental shuttle walk test, stair climbing) might predict complications, but still require further high-quality evaluation. SUMMARY: A straightforward way to better assess functional capacity is a structured interview with validated questionnaires or standardized questions about physical activities. Functional capacity can also be assessed by exercise tests, with the strongest evidence supporting CPET. Although some simpler exercise tests have shown promise, more research remains needed to better define their role in preoperative evaluation.

Drug Enforcement Agency 2014 Hydrocodone Rescheduling Rule and Opioid Dispensing after Surgery.

BACKGROUND: In 2014, the U.S. Drug Enforcement Agency reclassified hydrocodone from Schedule III to Schedule II of the Controlled Substances Act, resulting in new restrictions on refills. The authors hypothesized that hydrocodone rescheduling led to decreases in total opioid dispensing within 30 days of surgery and reduced new long-term opioid dispensing among surgical patients. METHODS: The authors studied privately insured, opioid-naïve adults undergoing 10 general or orthopedic surgeries between 2011 and 2015. The authors conducted a differences-in-differences analysis that compared overall opioid dispensing before versus after the rescheduling rule for patients treated by surgeons who frequently prescribed hydrocodone before rescheduling (i.e., patients who were functionally exposed to rescheduling's impact) while adjusting for secular trends via a comparison group of patients treated by surgeons who rarely prescribed hydrocodone (i.e., unexposed patients). The primary outcome was any filled opioid prescription between 90 and 180 days after surgery; secondary outcomes included the 30-day refill rate and the amount of opioids dispensed initially and at 30 days postoperatively. RESULTS: The sample included 65,136 patients. The percentage of patients filling a prescription beyond 90 days was similar after versus before rescheduling (absolute risk difference, -1.1%; 95% CI, -2.3% to 0.1%; P = 0.084). The authors estimated the rescheduling rule to be associated with a 45.4-mg oral morphine equivalent increase (difference-in-differences estimate; 95% CI, 34.2-56.7 mg; P < 0.001) in initial opioid dispensing, a 4.1% absolute decrease (95% CI, -5.5% to -2.7%; P < 0.001) in refills within 30 days, and a 37.7-mg oral morphine equivalent increase (95% CI, 20.6-54.8 mg; P = 0.008) in opioids dispensed within 30 days. CONCLUSIONS: Among patients treated by surgeons who frequently prescribed hydrocodone before the Drug Enforcement Agency 2014 hydrocodone rescheduling rule, rescheduling did not impact long-term opioid receipt, although it was associated with an increase in opioid dispensing within 30 days of surgery.

Socioeconomic Status and Days Alive and Out of Hospital after Major Elective Noncardiac Surgery: A Population-based Cohort Study.

BACKGROUND: Socioeconomic status is an important but understudied determinant of preoperative health status and postoperative outcomes. Previous work has focused on the impact of socioeconomic status on mortality, hospital stay, or complications. However, individuals with low socioeconomic status are also likely to have fewer supports to facilitate them remaining at home after hospital discharge. Thus, such patients may be less likely to return home over the short and intermediate term after major surgery. The newly validated outcome, days alive and out of hospital, may be highly suited to evaluating the impact of socioeconomic status on this postdischarge period. The study aimed to determine the association of socioeconomic status with short and intermediate term postoperative recovery as measured by days alive and out of hospital. METHODS: The authors evaluated data from 724,459 adult patients who had one of 13 elective major noncardiac surgical procedures between 2006 and 2017. Socioeconomic status was measured by median neighborhood household income (categorized into quintiles). Primary outcome was days alive and out of hospital at 30 days, while secondary outcomes included days alive and out of hospital at 90 and 180 days, and 30-day mortality. RESULTS: Compared to the highest income quintile, individuals in the lowest quintile had higher unadjusted risks of postoperative complications (6,049 of 121,099 [5%] vs. 6,216 of 160,495 [3.9%]) and 30-day mortality (731 of 121,099 [0.6%] vs. 701 of 160,495 [0.4%]) and longer mean postoperative length of stay (4.9 vs. 4.4 days). From lowest to highest income quintile, the mean adjusted days alive and out of hospital at 30 days after surgery varied between 24.5 to 24.9 days. CONCLUSIONS: Low socioeconomic status is associated with fewer days alive and out of hospital after surgery. Further research is needed to examine the underlying mechanisms and develop posthospital interventions to improve postoperative recovery in patients with fewer socioeconomic resources.

Integration of the Duke Activity Status Index into preoperative risk evaluation: a multicentre prospective cohort study.

BACKGROUND: The Duke Activity Status Index (DASI) questionnaire might help incorporate self-reported functional capacity into preoperative risk assessment. Nonetheless, prognostically important thresholds in DASI scores remain unclear. We conducted a nested cohort analysis of the Measurement of Exercise Tolerance before Surgery (METS) study to characterise the association of preoperative DASI scores with postoperative death or complications. METHODS: The analysis included 1546 participants (≥40 yr of age) at an elevated cardiac risk who had inpatient noncardiac surgery. The primary outcome was 30-day death or myocardial injury. The secondary outcomes were 30-day death or myocardial infarction, in-hospital moderate-to-severe complications, and 1 yr death or new disability. Multivariable logistic regression modelling was used to characterise the adjusted association of preoperative DASI scores with outcomes. RESULTS: The DASI score had non-linear associations with outcomes. Self-reported functional capacity better than a DASI score of 34 was associated with reduced odds of 30-day death or myocardial injury (odds ratio: 0.97 per 1 point increase above 34; 95% confidence interval [CI]: 0.96-0.99) and 1 yr death or new disability (odds ratio: 0.96 per 1 point increase above 34; 95% CI: 0.92-0.99). Self-reported functional capacity worse than a DASI score of 34 was associated with increased odds of 30-day death or myocardial infarction (odds ratio: 1.05 per 1 point decrease below 34; 95% CI: 1.00-1.09), and moderate-to-severe complications (odds ratio: 1.03 per 1 point decrease below 34; 95% CI: 1.01-1.05). CONCLUSIONS: A DASI score of 34 represents a threshold for identifying patients at risk for myocardial injury, myocardial infarction, moderate-to-severe complications, and new disability.

Assessment of functional capacity before major non-cardiac surgery: an international, prospective cohort study.

BACKGROUND: Functional capacity is an important component of risk assessment for major surgery. Doctors' clinical subjective assessment of patients' functional capacity has uncertain accuracy. We did a study to compare preoperative subjective assessment with alternative markers of fitness (cardiopulmonary exercise testing [CPET], scores on the Duke Activity Status Index [DASI] questionnaire, and serum N-terminal pro-B-type natriuretic peptide [NT pro-BNP] concentrations) for predicting death or complications after major elective non-cardiac surgery. METHODS: We did a multicentre, international, prospective cohort study at 25 hospitals: five in Canada, seven in the UK, ten in Australia, and three in New Zealand. We recruited adults aged at least 40 years who were scheduled for major non-cardiac surgery and deemed to have one or more risk factors for cardiac complications (eg, a history of heart failure, stroke, or diabetes) or coronary artery disease. Functional capacity was subjectively assessed in units of metabolic equivalents of tasks by the responsible anaesthesiologists in the preoperative assessment clinic, graded as poor (<4), moderate (4-10), or good (>10). All participants also completed the DASI questionnaire, underwent CPET to measure peak oxygen consumption, and had blood tests for measurement of NT pro-BNP concentrations. After surgery, patients had daily electrocardiograms and blood tests to measure troponin and creatinine concentrations until the third postoperative day or hospital discharge. The primary outcome was death or myocardial infarction within 30 days after surgery, assessed in all participants who underwent both CPET and surgery. Prognostic accuracy was assessed using logistic regression, receiver-operating-characteristic curves, and net risk reclassification. FINDINGS: Between March 1, 2013, and March 25, 2016, we included 1401 patients in the study. 28 (2%) of 1401 patients died or had a myocardial infarction within 30 days of surgery. Subjective assessment had 19·2% sensitivity (95% CI 14·2-25) and 94·7% specificity (93·2-95·9) for identifying the inability to attain four metabolic equivalents during CPET. Only DASI scores were associated with predicting the primary outcome (adjusted odds ratio 0·96, 95% CI 0·83-0·99; p=0·03). INTERPRETATION: Subjectively assessed functional capacity should not be used for preoperative risk evaluation. Clinicians could instead consider a measure such as DASI for cardiac risk assessment. FUNDING: Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Ontario Ministry of Health and Long-Term Care, Ontario Ministry of Research, Innovation and Science, UK National Institute of Academic Anaesthesia, UK Clinical Research Collaboration, Australian and New Zealand College of Anaesthetists, and Monash University.

Preoperative consultations for medicare patients undergoing cataract surgery.

IMPORTANCE: Low-risk elective surgical procedures are common, but there are no clear guidelines for when preoperative consultations are required. Such consultations may therefore represent a substantial discretionary service. OBJECTIVE: To assess temporal trends, explanatory factors, and geographic variation for preoperative consultation in Medicare beneficiaries undergoing cataract surgery, a common low-risk elective procedure. DESIGN, SETTING, AND PARTICIPANTS: Cohort study using a 5% national random sample of Medicare part B claims data including a cohort of 556,637 patients 66 years or older who underwent cataract surgery from 1995 to 2006. Temporal trends in consultations were evaluated within this entire cohort, whereas explanatory factors and geographic variation were evaluated within the 89,817 individuals who underwent surgery from 2005 to 2006. MAIN OUTCOMES AND MEASURES: Separately billed preoperative consultations (performed by family practitioners, general internists, pulmonologists, endocrinologists, cardiologists, nurse practitioners, or anesthesiologists) within 42 days before index surgery. RESULTS: The frequency of preoperative consultations increased from 11.3% in 1998 to 18.4% in 2006. Among individuals who underwent surgery in 2005 to 2006, hierarchical logistic regression modeling found several factors to be associated with preoperative consultation, including increased age (75-84 years vs 66-74 years: adjusted odds ratio [AOR], 1.09 [95% CI, 1.04-1.13]), race (African American race vs other: AOR, 0.71 [95% CI, 0.65-0.78]), urban residence (urban residence vs isolated rural town: AOR, 1.64 [95% CI, 1.49-1.81]), facility type (outpatient hospital vs ambulatory surgical facility: AOR, 1.10 [95% CI, 1.05-1.15]), anesthesia provider (anesthesiologist vs non-medically directed nurse anesthetist: AOR, 1.16 [95% CI, 1.10-1.24), and geographic region (Northeast vs South: AOR, 3.09 [95% CI, 2.33-4.10]). The burden of comorbidity was associated with consultation, but the effect size was small (<10%). Variation in frequency of consultation across hospital referral regions was substantial (median [range], 12% [0-69%]), even after accounting for differences in patient-level, anesthesia provider-level, and facility-level characteristics. CONCLUSIONS AND RELEVANCE: Between 1995 and 2006, the frequency of preoperative consultation for cataract surgery increased substantially. Referrals for consultation seem to be primarily driven by nonmedical factors, with substantial geographic variation.

Variation in the practice of preoperative medical consultation for major elective noncardiac surgery: a population-based study.

BACKGROUND: Patients scheduled for major elective noncardiac surgery frequently undergo preoperative medical consultations. However, the factors that determine whether individuals undergo consultation and the extent of interhospital variation remain unclear. METHODS: The authors used population-based administrative databases to conduct a cohort study of patients, aged 40 yr or older, who underwent major elective noncardiac surgery in Ontario, Canada, between April 2004 and February 2009. Multilevel logistic regression models were used to identify patient- and hospital-level predictors of consultation. RESULTS: Within the cohort of 204,819 patients who underwent surgery at 79 hospitals, 38% (n = 77,965) underwent preoperative medical consultation. Although patient- and surgery-level factors did predict consultation use, they explained only 5.9% of variation in consultation rates. Differences in rates across hospitals were large (range, 10-897 per 1,000 procedures), were not explained by surgical procedure volume or hospital teaching status, and persisted after adjustment for patient- and surgery-level factors. The median odds of undergoing consultation were 3.51 times higher if the same patient had surgery at one randomly selected hospital as opposed to another. CONCLUSIONS: One-third of surgical patients undergo preoperative medical consultation. Although patient- and surgery-level factors are weak predictors of consultation use, the individual hospital is the major determinant of whether patients undergo consultation. Additional research is needed to better understand the basis for this substantial interhospital variation and to determine which patients benefit most from preoperative consultation.

Outcomes and processes of care related to preoperative medical consultation.

BACKGROUND: Preoperative consultations by internal medicine physicians facilitate documentation of comorbid disease, optimization of medical conditions, risk stratification, and initiation of interventions intended to reduce risk. Nonetheless, the impact of these consultations, which may be performed by general internists or specialists, on outcomes is unclear. METHODS: We used population-based administrative databases to conduct a cohort study of patients 40 years or older who underwent major elective noncardiac surgery in Ontario, Canada, between 1994 and 2004. Propensity scores were used to assemble a matched-pairs cohort that reduced differences between patients who did and did not undergo preoperative consultation by general internists or specialists. The association of consultation with mortality and hospital stay was determined within this matched cohort. As a sensitivity analysis, we evaluated the association of consultation with an outcome for which no difference would be expected: postoperative wound infection. RESULTS: Of 269,866 patients in the cohort, 38.8% (n=104,695) underwent consultation. Within the matched cohort (n=191,852), consultation was associated with increased 30-day mortality (relative risk [RR], 1.16; 95% confidence interval [CI], 1.07-1.25; number needed to harm, 516), 1-year mortality (1.08; 1.04-1.12; number needed to harm, 227), mean hospital stay (difference, 0.67 days; 0.59-0.76), preoperative testing, and preoperative pharmacologic interventions. Notably, consultation was not associated with any difference in postoperative wound infections (RR, 0.98; 95% CI, 0.95-1.02). These findings were stable across subgroups as well as sensitivity analyses that tested for unmeasured confounding. CONCLUSIONS: Medical consultation before major elective noncardiac surgery is associated with increased mortality and hospital stay, as well as increases in preoperative pharmacologic interventions and testing. These findings highlight the need to better understand mechanisms by which consultation influences outcomes and to identify efficacious interventions to decrease perioperative risk.

Development of an algorithm to identify preoperative medical consultations using administrative data.

BACKGROUND: Preoperative consultation by internal medicine specialists may help improve the care of patients undergoing major surgery. Population-based administrative data are an efficient approach for studying these consultations at a population-level. However, administrative data in many jurisdictions lack specific codes to identify preoperative medical consultations, as opposed to consultations for nonoperative indications. OBJECTIVE: To develop an accurate claims-based algorithm for identifying preoperative medical consultations before major elective noncardiac surgery. RESEARCH DESIGN: We conducted a multicenter cross-sectional study in Ontario, Canada. Preoperative medical consultations identified by medical record abstraction were compared with those identified by linked administrative data (physician service claims, hospital discharge abstracts). SUBJECTS: We randomly selected 606 individuals, aged older than 40 years, who underwent elective intermediate-to-high-risk noncardiac surgery at 8 randomly selected hospitals between April 1, 2002 and March 31, 2004. RESULTS: Medical record abstraction identified preoperative medical consultations in 317 patients (52%). The optimal claims-based algorithm for identifying these consultations was a physician service claim for a consultation by a cardiologist, general internist, endocrinologist, geriatrician, or nephrologist within 4 months before the index surgical procedure. This algorithm had a sensitivity of 90% (95% confidence interval [CI]: 86-93), specificity of 92% (95% CI: 88-95), positive predictive value of 93% (95% CI: 89-95), and negative predictive value of 90% (95% CI: 86-93). CONCLUSIONS: A simple claims-based algorithm can accurately identify preoperative medical consultations before major elective noncardiac surgery. This algorithm may help enhance population-based evaluations of preoperative care, provided that the requisite linked administrative healthcare data are present.