Joseph A. Hyder

Association of Coronary Artery and Aortic Calcium With Lumbar Bone Density The MESA Abdominal Aortic Calcium Study

Atherosclerosis and osteoporosis share many risk factors, but their independent association is unclear. The authors investigated the independent associations between volumetric trabecular bone mineral density (vBMD) of the lumbar spine and coronary artery calcium (CAC) and abdominal aortic calcium (AAC). During 2002-2005, they used quantitative computed tomography to assess vBMD and the presence and extent of CAC and AAC among 946 women (mean age = 65.5 years) and 963 men (mean age = 64.1 years) in a substudy of the Multi-Ethnic Study of Atherosclerosis. Prevalences of CAC were 47% and 68% in women and men, respectively, and AAC prevalences were 70% and 73%. Sequential, sex-specific regression models included adjustment for age, ethnicity, body mass index, hypertension, dyslipidemia, diabetes mellitus, smoking, alcohol consumption, physical activity, interleukin-6, C-reactive protein, homocysteine, and sex hormones. After full adjustment, lower vBMD was associated with greater CAC score among women (P < 0.002) and greater AAC score among women (P = 0.004) and men (P < 0.001). After adjustment, vBMD quartile was inversely associated with CAC prevalence (P-trend = 0.05) in women and AAC prevalence (P-trend < 0.01) in men. Partially and fully adjusted models showed similar results. Though modest, these significant, independent associations suggest that atherosclerosis and bone loss may be related.

The Provision of Surgical Care by International Organizations in Developing Countries: A Preliminary Report

ObjectiveEmerging data demonstrate that a large fraction of the global burden of disease is amenable to surgical intervention. There is a paucity of data related to delivery of surgical care in low- and middle-income countries, and no aggregate data describe the efforts of international organizations to provide surgical care in these settings. This study was designed to describe the roles and practices of international organizations delivering surgical care in developing nations with regard to surgical types and volume, outcomes tracking, and degree of integration with local health systems.MethodsBetween October 2008 and December 2008, an Internet-based confidential questionnaire was distributed to 99 international organizations providing humanitarian surgical care to determine their size, scope, involvement in surgical data collection, and integration into local systems.ResultsForty-six international organizations responded (response rate 46%). Findings reveal that a majority of organizations that provide surgery track numbers of cases performed and immediate outcomes, such as mortality. In general, these groups have mechanisms in place to track volume and outcomes, provide for postintervention follow-up, are committed to providing education, and work in conjunction with local health organizations and providers. Whereas most organizations surveyed provided fewer than 500 surgical procedures annually, more than half had the capacity to provide emergency services. In addition, a great diversity of specialized surgical care was provided, including obstetrics, orthopedic, plastic, and ophthalmologic surgery.ConclusionsInternational organizations providing surgical services are diverse in size and breadth of surgical services provided yet, with consistency, provide rudimentary analysis, postoperative follow-up care, and both education and integration of health services at the local level. The role of international organizations in the delivery of surgery is an important index, worthy of further evaluation.

Bone mineral density and atherosclerosis: The Multi-Ethnic Study of Atherosclerosis, Abdominal Aortic Calcium Study

CONTEXT Molecular and cell biology studies have demonstrated an association between bone and arterial wall disease, but the significance of a population-level association is less clear and potentially confounded by inability to account for shared risk factors. OBJECTIVE To test population-level associations between atherosclerosis types and bone integrity. MAIN OUTCOME MEASURES Volumetric trabecular lumbar bone mineral density (vBMD), ankle-brachial index (ABI), intima-media thickness (IMT) of the common carotid (CCA-IMT) and internal carotid (ICA-IMT) arteries, and carotid plaque echogenicity. DESIGN, SETTING AND PARTICIPANTS A random subset of participants from the Multi-Ethnic Study of Atherosclerosis (MESA) assessed between 2002 and 2005. RESULTS 904 post-menopausal female (62.4 years; 62% non-white; 12% ABI <1; 17% CCA-IMT >1mm; 33% ICA-IMT >1mm) and 929 male (61.4 years; 58% non-white; 6% ABI <1; 25% CCA-IMT >1mm; 40% ICA-IMT >1mm) were included. In serial, sex-specific regression models adjusting for age, ethnicity, body mass index, dyslipidemia, hypertension, smoking, alcohol consumption, diabetes, homocysteine, interleukin-6, sex hormones, and renal function, lower vBMD was associated with lower ABI in men (p for trend <0.01) and greater ICA-IMT in men (p for trend <0.02). CCA-IMT was not associated with vBMD in men or women. Carotid plaque echogenicity was independently associated with lower vBMD in both men (trend p=0.01) and women (trend p<0.04). In all models, adjustment did not materially affect results. CONCLUSIONS Lower vBMD is independently associated with structural and functional measures of atherosclerosis in men and with more advanced and calcified carotid atherosclerotic plaques in both sexes.

Antibiotic Use in Thailand: Quantifying Impact on Blood Culture Yield and Estimates of Pneumococcal Bacteremia Incidence

No studies have quantified the impact of pre-culture antibiotic use on the recovery of individual blood-borne pathogens or on population-level incidence estimates for Streptococcus pneumoniae. We conducted bloodstream infection surveillance in Thailand during November 2005–June 2008. Pre-culture antibiotic use was assessed by reported use and by serum antimicrobial activity. Of 35,639 patient blood cultures, 27% had reported pre-culture antibiotic use and 24% (of 24,538 tested) had serum antimicrobial activity. Pathogen isolation was half as common in patients with versus without antibiotic use; S. pneumoniae isolation was 4- to 9-fold less common (0.09% versus 0.37% by reported antibiotic use; 0.05% versus 0.45% by serum antimicrobial activity, P < 0.01). Pre-culture antibiotic use by serum antimicrobial activity reduced pneumococcal bacteremia incidence by 32% overall and 39% in children < 5 years of age. Our findings highlight the limitations of culture-based detection methods to estimate invasive pneumococcal disease incidence in settings where pre-culture antibiotic use is common.

Burden of Surgical Disease: Strategies to Manage an Existing Public Health Emergency

The World Health Organization estimates that the burden of surgical disease due to war, self-inflicted injuries, and road traffic incidents will rise dramatically by 2020. During the 2009 Harvard Humanitarian Initiatives Humanitarian Action Summit (HHI/HAS),members of the Burden of Surgical Disease Working Group met to review the state of surgical epidemiology, the unmet global surgical need, and the role international organizations play in filling the surgical gap during humanitarian crises, conflict, and war. An outline of the groups findings and recommendations is provided.

Risk and Patterns of Secondary Complications in Surgical Inpatients

IMPORTANCE Little empirical evidence exists on how a first (index) complication influences the risk of specific subsequent secondary complications. Understanding these risks is important to elucidate clinical pathways of failure to rescue or death after postoperative complication. OBJECTIVE To understand patterns of secondary complications in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP). DESIGN, SETTING, AND PARTICIPANTS Matched analysis using a cohort of 890 604 patients undergoing elective inpatient surgery from January 1, 2005, through December 31, 2011, identified in the NSQIP Participant Use Data File. Five index complications were studied: pneumonia, acute myocardial infarction, deep space surgical site infection, bleeding or transfusion event, and acute renal failure. Each patient with an index complication was matched to a control patient based on propensity for the index event and the number of event-free days. Outcomes were compared using conditional logistic regression. MAIN OUTCOMES AND MEASURES Rates of 30-day secondary complications and 30-day mortality. RESULTS Five cohorts were developed, each with 1:1 matching to controls, which were well balanced. Index pneumonia (n = 7947) was associated with increased odds of 30-day reintubation (odds ratio [OR], 17.1; 95% CI, 13.8-21.3; P < .001), ventilatory failure (OR, 15.9; 95% CI, 12.8-19.8; P < .001), sepsis (OR, 7.3; 95% CI, 6.2-8.6; P < .001), and shock (OR, 13.0; 95% CI, 10.4-16.2; P < .001). Index acute myocardial infarction was associated with increased rates of secondary bleeding or transfusion events (OR, 4.3; 95% CI, 3.3-5.8; P < .001), pneumonia (OR, 5.1; 95% CI, 2.6-10.2; P < .001), cardiac arrest (OR, 12.0; 95% CI, 7.5-19.2; P < .001), and reintubation (OR, 11.7; 95% CI, 8.4-16.3; P < .001). Deep space surgical site infection was associated with dehiscence (OR, 30.4; 95% CI, 19.9-46.5; P < .001), sepsis (OR, 13.1; 95% CI, 10.2-16.7; P < .001), shock (OR, 10.6; 95% CI, 6.4-17.7; P < .001), kidney injury (OR, 8.6; 95% CI, 3.9-18.8; P < .001), and acute renal failure (OR, 10.5; 95% CI, 3.8-29.3; P < .001). Index acute renal failure was associated with increased odds of cardiac arrest (OR, 25.3; 95% CI, 9.3-68.6; P < .001), reintubation (OR, 11.3; 95% CI, 7.4-17.1; P < .001), ventilatory failure (OR, 12.4; 95% CI, 8.2-18.8; P < .001), bleeding or transfusion events (OR, 11.3; 95% CI, 6.3-20.5; P < .001), and shock (OR, 11.2; 95% CI, 7.2-17.3; P < .001). CONCLUSIONS AND RELEVANCE This investigation quantified the effect of index complications on patient risk of specific secondary complications. The defined pathways merit investigation as unique targets for quality improvement and benchmarking.

Safety of Overlapping Surgery at a High-volume Referral Center

Objective: To compare safety profiles of overlapping and nonoverlapping surgical procedures at a large tertiary-referral center where overlapping surgery is performed. Background: Surgical procedures are frequently performed as overlapping, wherein one surgeon is responsible for 2 procedures occurring at the same time, but critical portions are not coincident. The safety of this practice has not been characterized. Methods: Primary analyses included elective, adult, inpatient surgical procedures from January 2013 to September 2015 available through University HealthSystem Consortium. Overlapping and nonoverlapping procedures were matched in an unbalanced manner (m:n) by procedure type. Confirmatory analyses from the American College of Surgeons-National Surgical Quality Improvement Program investigated elective surgical procedures from January 2011 to December 2014. We compared outcomes mortality and length of stay after adjustment for registry-predicted risk, case-mix, and surgeon using mixed models. Results: The University HealthSystem Consortium sample included 10,765 overlapping cases, of which 10,614 (98.6%) were matched to 16,111 nonoverlapping procedures. Adjusted odds ratio for inpatient mortality was greater for nonoverlapping procedures (adjusted odds ratio, OR = 2.14 vs overlapping procedures; 95% confidence interval, CI 1.23–3.73; P = 0.007) and length of stay was no different (+1% for nonoverlapping cases; 95% CI, −1% to +2%; P = 0.50). In confirmatory analyses, 93.7% (3712/3961) of overlapping procedures matched to 5,637 nonoverlapping procedures. The 30-day mortality (adjusted OR = 0.69 nonoverlapping vs overlapping procedures; 95% CI, 0.13–3.57; P = 0.65), morbidity (adjusted OR = 1.11; 95% CI, 0.92–1.35; P = 0.27) and length of stay (−4% for nonoverlapping; 95% CI, −4% to −3%; P < 0.001) were not clinically different. Conclusions: These findings from administrative and clinical registries support the safety of overlapping surgical procedures at this center but may not extrapolate to other centers.

Anesthesia Care Transitions and Risk of Postoperative Complications.

BACKGROUND:A patient undergoing surgery may receive anesthesia care from several anesthesia providers. The safety of anesthesia care transitions has not been evaluated. Using unconditional and conditional multivariable logistic regression models, we tested whether the number of attending anesthesiologists involved in an operation was associated with postoperative complications. METHODS:In a cohort of patients undergoing elective colorectal surgical in an academic tertiary care center with a stable anesthesia care team model participating in the American College of Surgeons National Surgical Quality Improvement Program, using unconditional and conditional multivariable logistic regression models, we tested adjusted associations between numbers of attending anesthesiologists and occurrence of death or a major complication (acute renal failure, bleeding that required a transfusion of 4 units or more of red blood cells within 72 hours after surgery, cardiac arrest requiring cardiopulmonary resuscitation, coma of 24 hours or longer, myocardial infarction, unplanned intubation, ventilator use for 48 hours or more, pneumonia, stroke, wound disruption, deep or organ-space surgical-site infection, superficial surgical-site infection, sepsis, septic shock, systemic inflammatory response syndrome). RESULTS:We identified 927 patients who underwent elective colectomy of comparable surgical intensity. In all, 71 (7.7%) patients had major nonfatal complications or death. One anesthesiologist provided care for 530 (57%) patients, 2 anesthesiologists for 287 (31%), and 3 or more for 110 (12%). The number of attending anesthesiologists was associated with increased odds of postoperative complication (unadjusted odds ratio [OR] = 1.52, 95% confidence interval [CI] 1.18–1.96, P = 0.0013; adjusted OR = 1.44, 95% CI 1.09–1.91, P = 0.0106). In sensitivity analyses, occurrence of a complication was significantly associated with the number of in-room providers, defined as anesthesia residents and nurse anesthetists (adjusted OR = 1.39, 95% CI 1.01–1.92, P = 0.0446) and for all anesthesia providers (adjusted OR = 1.58, 95%CI 1.20–2.08, P = 0.0012). Findings persisted across multiple, alternative adjustments, sensitivity analyses, and conditional logistic regression with matching on operative duration. CONCLUSIONS:In our study, care by additional attending anesthesiologists and in-room providers was independently associated with an increased odds of postoperative complications. These findings challenge the assumption that anesthesia transitions are care neutral and not contributory to surgical outcomes.

The association of bone density and calcified atherosclerosis is stronger in women without dyslipidemia: The multi-ethnic study of atherosclerosis

We tested whether the association between bone mineral density (BMD) and coronary artery calcification (CAC) varies according to dyslipidemia in community‐living individuals. Between 2002 and 2005, 305 women and 631 men (mean age of 64 years), who were not taking lipid‐lowering medications or estrogen were assessed for spine BMD, CAC, and total (TC), HDL‐ and LDL‐cholesterol and triglycerides. Participants were a random sample from the Multi‐Ethnic Study of Atherosclerosis (MESA) without clinical cardiovascular disease. Spine BMD at the L3 vertebrate was performed by computer tomography (CT). CAC prevalence was measured by CT. The total cholesterol to HDL ratio (TC:HDL) ≥ 5.0 was used as the primary marker of hyperlipidemia. The association of BMD with CAC differed in women with TC:HDL < 5.0 versus higher (p‐interaction = 0.01). In age‐ and race‐adjusted models, among women with TC:HDL < 5.0, each SD (43.4 mg/cc) greater BMD was associated with a 25% lower prevalence of CAC (prevalence ratio [PR] 0.75, 95% confidence interval [CI] 0.63–0.89), whereas among women with higher TC:HDL, higher BMD was not significantly associated with CAC (PR 1.22, 95% CI 0.82–1.82). Results were similar using other definitions of hyperlipidemia. In contrast, no consistent association was observed between BMD and CAC in men, irrespective of the TC:HDL ratio (p interaction 0.54). The inverse association of BMD with CAC is stronger in women without dyslipidemia. These data argue against the hypothesis that dyslipidemia is the key factor responsible for the inverse association of BMD with atherosclerosis.

Hospital-level Variation in Secondary Complications After Surgery.

Objectives:To assess whether hospital rates of secondary complications could serve as a performance benchmark and examine associations with mortality. Background:Failure to rescue (death after postoperative complication) is a challenging target for quality improvement. Secondary complications (complications after a first or “index” complication) are intermediate outcomes in the rescue process that may provide specific improvement targets and give us insight into how rescue fails. Methods:We used American College of Surgeons’ National Surgical Quality Improvement Program data (2008–2012) to define hospital rates of secondary complications after 5 common index complications: pneumonia, surgical site infection (SSI), urinary tract infection, transfusion/bleed events, and acute myocardial infarction (MI). Hospitals were divided into quintiles on the basis of risk- and reliability-adjusted rates of secondary complications, and these rates were compared along with mortality. Results:A total of 524,860 patients were identified undergoing one of the 62 elective, inpatient operations. After index pneumonia, secondary complication rates varied from 57.99% in the highest quintile to 22.93% in the lowest [adjusted odds ratio (OR), 4.64; confidence interval (CI), 3.95–5.45). Wide variation was seen after index SSI (58.98% vs 14.81%; OR, 8.53; CI, 7.41–9.83), urinary tract infection (38.41% vs 8.60%; OR, 7.81; CI, 6.48–9.40), transfusion/bleeding events (27.14% vs 12.88%; OR, 2.54; CI, 2.31–2.81), and acute MI (64.45% vs 23.86%, OR, 6.87; CI, 5.20–9.07). Hospitals in the highest quintile had significantly greater mortality after index pneumonia (10.41% vs 6.20%; OR, 2.17; CI, 1.6–2.94), index MI (18.25% vs 9.65%; OR, 2.67; CI, 1.80–3.94), and index SSI (2.75% vs 0.82%; OR, 3.93; CI, 2.26–6.81). Conclusions:Hospital-level rates of secondary complications (failure to arrest complications) vary widely, are associated with mortality, and may be useful for quality improvement and benchmarking.