Faculty Bibliography

Purpose To investigate whether assessment of bone strength with quantitative computed tomography (CT) in combination with dual-energy x-ray absorptiometry (DXA) is cost-effective as a screening tool for osteoporosis in postmenopausal women. Materials and Methods A state-transition microsimulation model of osteoporosis for postmenopausal women aged 55 years or older was developed with a lifetime horizon and U.S. societal perspective. All model inputs were derived from published literature. Three strategies were compared: no screening, DXA with T score-dependent rescreening intervals, and a combination of DXA and quantitative CT with different intervals (3, 5, and 10 years) at different screening initiation ages (55-65 years). Oral bisphosphonate therapy was started if DXA hip T scores were less than or equal to -2.5, 10-year risk for hip fracture was greater than 3% (World Health Organization Fracture Risk Assessment Tool score, or FRAX), 10-year risk for major osteoporotic fracture was greater than 20% (FRAX), quantitative CT femur bone strength was less than 3000 N, or occurrence of first fracture (eg, hip, vertebral body, wrist). Outcome measures were incremental cost-effectiveness ratios (ICERs) in 2015 U.S. dollars per quality-adjusted life year (QALY) gained and number of fragility fractures. Probabilistic sensitivity analysis was also performed. Results The most cost-effective strategy was combined DXA and quantitative CT screening starting at age 55 with quantitative CT screening every 5 years (ICER, $2000 per QALY). With this strategy, 12.8% of postmenopausal women sustained hip fractures in their remaining life (no screening, 18.7%; DXA screening, 15.8%). The corresponding percentages of vertebral fractures for DXA and quantitative CT with a 5-year interval, was 7.5%; no screening, 11.1%; DXA screening, 9%; for wrist fractures, 14%, 17.8%, and 16.4%, respectively; for other fractures, 22.6%, 30.8%, and 27.3%, respectively. In probabilistic sensitivity analysis, DXA and quantitative CT at age 55 years with quantitative CT screening every 5 years was the best strategy in more than 90% of all 1000 simulations (for thresholds of $50 000 per QALY and $100 000 per QALY). Conclusion Combined assessment of bone strength and bone mineral density is a cost-effective strategy for osteoporosis screening in postmenopausal women and has the potential to prevent a substantial number of fragility fractures. (c) RSNA, 2017 Online supplemental material is available for this article.

BACKGROUND: Because of confounding from the urban/rural and socioeconomic organizations of territories and resulting correlation between residential and nonresidential exposures, classically estimated residential neighborhood-outcome associations capture nonresidential environment effects, overestimating residential intervention effects. Our study diagnosed and corrected this "residential" effect fallacy bias applicable to a large fraction of neighborhood and health studies. METHODS: Our empirical application investigated the effect that hypothetical interventions raising the residential number of services would have on the probability that a trip is walked. Using global positioning systems (GPS) tracking and mobility surveys over 7 days (227 participants, 7440 trips), we employed a multilevel linear probability model to estimate the trip-level association between residential number of services and walking to derive a naive intervention effect estimate; and a corrected model accounting for numbers of services at the residence, trip origin, and trip destination to determine a corrected intervention effect estimate (true effect conditional on assumptions). RESULTS: There was a strong correlation in service densities between the residential neighborhood and nonresidential places. From the naive model, hypothetical interventions raising the residential number of services to 200, 500, and 1000 were associated with an increase by 0.020, 0.055, and 0.109 of the probability of walking in the intervention groups. Corrected estimates were of 0.007, 0.019, and 0.039. Thus, naive estimates were overestimated by multiplicative factors of 3.0, 2.9, and 2.8. CONCLUSIONS: Commonly estimated residential intervention-outcome associations substantially overestimate true effects. Our somewhat paradoxical conclusion is that, to estimate residential effects, investigators critically need information on nonresidential places visited.

OBJECTIVE: To provide a multi-institutional analysis of clinical factors predicting unplanned hospital readmission after major inpatient urologic surgery. MATERIALS AND METHODS: The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) is a risk-adjusted data collection mechanism for analyzing clinical outcomes data including 30-day perioperative readmissions and complications. We identified 23,108 patients who underwent major inpatient urologic surgery from 2011 to 2012. Readmission rates were determined and stratified by procedure type. Multiple logistic regression was used to determine independent risk factors for 30-day unplanned hospital readmissions. RESULTS: Of 23,108 total patients undergoing urologic surgery, 1329 patients (5.8%) had unplanned readmissions. Upper tract reconstruction and urinary diversion without cystectomy (21/102) and cystectomy (291/1,662) had the highest rates of readmission of all procedures analyzed. Readmitted patients had a 64.2% (853/1329) and 64.4% (855/1329 patients) rate of major and minor complications, respectively, compared to 6.7% (1459/21779) and 15.9% (3462/21779) for patients not readmitted (p<0.02). Organ space infection (OR 15.23), pulmonary embolism (OR 12.14), deep venous thrombosis (OR 10.96), and return to the operating room (OR 8.46) were the most substantial predictors of readmission. Laparoscopic/robotic procedures had significantly lower readmission rates compared to open procedures for prostatectomy, partial nephrectomy, and nephrectomy (p<0.01). CONCLUSIONS: Readmission after inpatient urological surgery occurs at a rate of 5.8%, with cystectomy and urinary diversion demonstrating the highest rates. Major and minor postoperative complications were the most substantial predictors of readmission. These results may guide risk reduction initiatives to prevent readmissions after major urologic surgery.

OBJECTIVE:and diabetes duration) with brain volumes and vascular pathology on brain MRI and to assess whether the associations of diabetes with brain volumes are mediated by brain vascular pathology. RESEARCH DESIGN AND METHODS:≥6.5%] <7.0% vs. ≥7.0%), with further stratification by diabetes duration (<10 vs. ≥10 years). RESULTS:> 0.05). CONCLUSIONS:and longer disease duration) but not prediabetes or less-severe diabetes was associated with smaller brain volumes and an increased burden of brain vascular pathology. No evidence was found that associations of diabetes with smaller brain volumes are mediated by brain vascular pathology, suggesting that other mechanisms may be responsible for these associations.

OBJECTIVES: This study aimed to evaluate the acceptability of smartphone-based text message- and voice-based ecological momentary assessment (EMA) methods among a sample of low-income housing residents in New York City. Using data from the community-based NYC Low Income Housing, Neighborhoods and Health Study (n = 112), the acceptability of text message- and voice-based EMA methods were assessed via survey. RESULTS: Overall, 88.4% of participants reported that they would participate in a study that utilized text message-based EMA. These analyses showed no appreciable differences by sub-groups (p > .05). Overall, 80.2% of participants reported that they would participate in a study that used voice-based EMA. This voice-based method was least acceptable among participants younger than 25 years old compared to participants of all other ages, chi2(2) = 10.107, p = .006 (among the younger participants 60.7% reported "yes" regarding the anticipated acceptability of voice-based EMA and 39.3% reported "no"). Overall, this work suggests that text message- and voice-based EMA methods are acceptable for use among low-income housing residents. However, the association between age and the acceptability of voice-based EMA suggests that these methods may be less suited for younger populations.

BACKGROUND: The Mullerian ducts are the embryological precursors of the female reproductive tract, including the uterus; anti-Mullerian hormone (AMH) has a key role in the regulation of foetal sexual differentiation. Anti-Mullerian hormone inhibits endometrial tumour growth in experimental models by stimulating apoptosis and cell cycle arrest. To date, there are no prospective epidemiologic data on circulating AMH and endometrial cancer risk. METHODS: We investigated this association among women premenopausal at blood collection in a multicohort study including participants from eight studies located in the United States, Europe, and China. We identified 329 endometrial cancer cases and 339 matched controls. Anti-Mullerian hormone concentrations in blood were quantified using an enzyme-linked immunosorbent assay. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI) across tertiles and for a doubling of AMH concentrations (ORlog2). Subgroup analyses were performed by ages at blood donation and diagnosis, oral contraceptive use, and tumour characteristics. RESULTS: Anti-Mullerian hormone was not associated with the risk of endometrial cancer overall (ORlog2: 1.07 (0.99-1.17)), or with any of the examined subgroups. CONCLUSIONS: Although experimental models implicate AMH in endometrial cancer growth inhibition, our findings do not support a role for circulating AMH in the aetiology of endometrial cancer.British Journal of Cancer advance online publication 5 September 2017; doi:10.1038/bjc.2017.299 www.bjcancer.com.

The global nephrology community recognises the need for a cohesive plan to address the problem of chronic kidney disease (CKD). In July, 2016, the International Society of Nephrology hosted a CKD summit of more than 85 people with diverse expertise and professional backgrounds from around the globe. The purpose was to identify and prioritise key activities for the next 5-10 years in the domains of clinical care, research, and advocacy and to create an action plan and performance framework based on ten themes: strengthen CKD surveillance; tackle major risk factors for CKD; reduce acute kidney injury-a special risk factor for CKD; enhance understanding of the genetic causes of CKD; establish better diagnostic methods in CKD; improve understanding of the natural course of CKD; assess and implement established treatment options in patients with CKD; improve management of symptoms and complications of CKD; develop novel therapeutic interventions to slow CKD progression and reduce CKD complications; and increase the quantity and quality of clinical trials in CKD. Each group produced a prioritised list of goals, activities, and a set of key deliverable objectives for each of the themes. The intended users of this action plan are clinicians, patients, scientists, industry partners, governments, and advocacy organisations. Implementation of this integrated comprehensive plan will benefit people who are at risk for or affected by CKD worldwide.

BACKGROUND: Hepatitis C virus (HCV) is a persistent epidemic among people who inject drugs (PWID), and PWID remain as the population experiencing the most significant impact of HCV-related morbidity and mortality worldwide. OBJECTIVE: The purpose of this systematic review and meta-analysis is to synthesize data on the epidemiology of HCV infection among PWID. Our main objectives are to characterize the global and regional distribution and determinants of HCV infection among PWID. METHODS: A search strategy is conducted that involves both the electronic and manual retrievals of literature. Reports are included in this review if they present data published between 2006 and 2015 on prevalent or incident HCV infection among current or former PWID. Standard meta-analytic techniques are performed to synthesize the pooled data and identify correlates of HCV infection. RESULTS: The search strategy has been performed, and data collection is in progress. Data analysis will follow, and the final results of this systematic review/meta-analysis are expected by December 2017. CONCLUSIONS: This article describes the protocol for the systematic review and meta-analysis of epidemiology of HCV among PWID. We aim to provide synthesized data on HCV incidence and prevalence as well as to identify factors associated with HCV transmission. Our research contributes empirical evidence that informs scholarly, medical, and policy discussions concerning HCV. TRIAL REGISTRATION: PROSPERO CRD42016035687; https://www.crd.york.ac.uk/prospero/display_record.asp? ID=CRD42016035687 (Archived by WebCite at http://www.webcitation.org/6ttYLn65N).

Glycemic excursions, independent of average glucose, have been implicated in the development of diabetic complications. It is unknown whether low levels of 1,5-anhydroglucitol (1,5-AG) are associated with advanced stages of kidney disease independent of kidney function and glycemia. In the Atherosclerosis Risk in Communities Study (n = 13,277 from 4 US communities), we used structural equation modeling to estimate the association between serum 1,5-AG levels and end-stage renal disease (ESRD) from baseline (1990-1992) through 2013 with adjustment for demographics, risk factors, a latent variable for glycemia (diabetes status, fasting glucose, glycated hemoglobin (HbA1c), fructosamine, glycated albumin), and a latent variable for kidney function (creatinine, cystatin C, β2-microglobulin). After adjusting for demographics, risk factors, and the latent variable for kidney function, the linear spline terms representing 1,5-AG levels <6.0 μg/mL (incidence rate ratio (IRR) = 0.79, 95% confidence interval (CI): 0.70, 0.88) and 6.0-9.9 μg/mL (IRR = 0.80, 95% CI: 0.70, 0.92) were significantly associated with ESRD. After additionally adjusting for the latent variable for glycemia, low 1,5-AG levels (<6.0 μg/mL) were no longer significantly associated with ESRD (IRR = 0.92, 95% CI: 0.81, 1.05). In conclusion, low 1,5-AG levels are associated with higher risk of incident ESRD independent of baseline kidney function but not independent of glycemia.

BACKGROUND:Hypo- and hyperkalemia in clinical settings are insufficiently characterized and large-scale data from Europe lacking. We studied incidence and determinants of these abnormalities in a large Swedish healthcare system. METHODS:Observational study from the Stockholm CREAtinine Measurements project, including adult individuals from Stockholm accessing healthcare in 2009 (n=364,955). Over 3-years, we estimated the incidence of hypokalemia, defined as potassium<3.5mmol/L, hyperkalemia, defined as potassium>5mmol/L, and moderate/severe hyperkalemia, defined as potassium>5.5mmol/L. Kidney function was assessed by estimated glomerular filtration rate (eGFR). RESULTS:Of 364,955 participants, 69.4% had 1-2 potassium tests, 16.7% had 3-4 tests and the remaining 13.9% had >4potassiumtests/year. Hypokalemia occurred in 49,662 (13.6%) individuals, with 33% recurrence. Hyperkalemia occurred in 25,461 (7%) individuals, with 35.7% recurrence. Moderate/severe hyperkalemia occurred in 9059 (2.5%) with 28% recurrence. The frequency of potassium testing was an important determinant of dyskalemia risk. The incidence proportion of hyperkalemia was higher in the presence of diabetes, lower eGFR, myocardial infarction, heart failure (HF), or use of renin angiotensin-aldosterone system inhibitors (RAASi). In adjusted analyses, women and use of loop/thiazide diuretics were associated with lower hyperkalemia risk. Older age, lower eGFR, diabetes, HF and use of RAASi were associated with higher hyperkalemia risk. On the other hand, women, younger age, higher eGFR and baseline use of diuretics were associated with higher hypokalemia risk. CONCLUSION/CONCLUSIONS:Hypo- and hyperkalemia are common in healthcare. Optimal RAASi and diuretics use and careful potassium monitoring in the presence of certain comorbidities, especially lower eGFR, is advocated.