Rodrigo B. Cavalcanti

A randomized, placebo-controlled trial of rosiglitazone for HIV-related lipoatrophy.

BACKGROUND Thiazolidinediones such as rosiglitazone may have benefit in ameliorating human immunodeficiency virus (HIV) lipoatrophy. METHODS HIV-positive patients receiving stable, protease inhibitor-containing highly active antiretroviral therapy with HIV lipodystrophy were prospectively randomized to rosiglitazone (4 mg/day) or placebo. The primary end point was the 24-week percentage change in arm fat by dual-energy x-ray absorptiometry (DEXA). Clinical and anthropometric evaluations, fasting lipid parameters, oral glucose tolerance testing, CD36 expression, quality of life measures, and DEXA scanning were performed at baseline and week 24. RESULTS Seventy-eight of the 96 enrolled patients were evaluated. Median age was 46.8 years, 97.4% were male, and 54% were treated with thymidine analogues. Median baseline limb fat was 3.76 and 2.99 kg in the rosiglitazone and control groups, respectively. Median changes in arm, leg, trunk, and total body fat at 24 weeks were not significantly different between groups (7.1% vs. 5.0% [P=.94]; 0.1% vs. -2.4% [P=.90]; 1.2% vs. -1.4% [P=.81]; and 1.7% vs. 0.4% [P=.76]). There were no significant changes in secondary end points. There was no correlation between changes in body fat or treatment-arm and CD36 expression. CONCLUSIONS This randomized, placebo-controlled trial did not show benefit of 4 mg/day of rosiglitazone on lipoatrophy or metabolic parameters in patients with HIV lipodystrophy.

Limitations of subjective cognitive load measures in simulation‐based procedural training

The effective implementation of cognitive load theory (CLT) to optimise the instructional design of simulation‐based training requires sensitive and reliable measures of cognitive load. This mixed‐methods study assessed relationships between commonly used measures of total cognitive load and the extent to which these measures reflected participants’ experiences of cognitive load in simulation‐based procedural skills training.

The intended and unintended consequences of communication systems on general internal medicine inpatient care delivery: a prospective observational case study of five teaching hospitals.

BACKGROUND Effective clinical communication is critical to providing high-quality patient care. Hospitals have used different types of interventions to improve communication between care teams, but there have been few studies of their effectiveness. OBJECTIVES To describe the effects of different communication interventions and their problems. DESIGN Prospective observational case study using a mixed methods approach of quantitative and qualitative methods. SETTING General internal medicine (GIM) inpatient wards at five tertiary care academic teaching hospitals. PARTICIPANTS Clinicians consisting of residents, attending physicians, nurses, and allied health (AH) staff working on the GIM wards. METHODS Ethnographic methods and interviews with clinical staff (doctors, nurses, medical students, and AH professionals) were conducted over a 16-month period from 2009 to 2010. RESULTS We identified four categories that described the intended and unintended consequences of communication interventions: impacts on senders, receivers, interprofessional collaboration, and the use of informal communication processes. The use of alphanumeric pagers, smartphones, and web-based communication systems had positive effects for senders and receivers, but unintended consequences were seen with all interventions in all four categories. CONCLUSIONS Interventions that aimed to improve clinical communications solved some but not all problems, and unintended effects were seen with all systems.

It's not about pager replacement: an in-depth look at the interprofessional nature of communication in healthcare.

BACKGROUND Institutions have tried to replace the use of numeric pagers for clinical communication by implementing health information technology (HIT) solutions. However, failing to account for the sociotechnical aspects of HIT or the interplay of technology with existing clinical workflow, culture, and social interactions may create other unintended consequences. OBJECTIVE To evaluate a Web-based messaging system that allows asynchronous communication between health providers and identify the unintended consequences associated with implementing such technology. DESIGN Intervention-a Web-based messaging system at the University Health Network to replace numeric paging practices in May 2010. The system facilitated clinical communication on the medical wards for coordinating patient care. Study design-pre-post mixed methods utilizing both quantitative and qualitative measures. PARTICIPANTS Five residents, 8 nurses, 2 pharmacists, and 2 social workers were interviewed. Pre-post interruption-15 residents from 5 clinical teams in both periods. MEASUREMENTS The study compared the type of messages sent to physicians before and after implementation of the Web-based messaging system; a constant comparative analysis of semistructured interviews was used to generate key themes related to unintended consequences. RESULTS Interruptions increased 233%, from 3 pages received per resident per day pre-implementation to 10 messages received per resident per day post-implementation. Key themes relating to unintended consequences that emerged from the interviews included increase in interruptions, accountability, and tactics to improve personal productivity. CONCLUSIONS Meaningful improvements in clinical communication can occur but require more than just replacing pagers. Introducing HIT without addressing the sociotechnical aspects of HIT that underlie clinical communication can lead to unintended consequences.

A Meta-Analysis of Six Placebo-Controlled Trials of Thiazolidinedione Therapy for HIV Lipoatrophy

Abstract Objective: To determine the impact of thiazolidinediones (TZD) on changes in limb fat mass in HIV-infected individuals, particularly in those not receiving a thymidine analogue.Methods: Individual patient data from placebo-controlled, randomized trials of rosiglitazone (n = 5) or pioglitazone (n = 1) were combined. Generalized estimating equation (GEE) models were used to estimate the treatment effect on changes in limb fat mass.Results: In the combined dataset of 427 patients, the baseline median age was 45 years, 86% were male, 80% were Caucasian, 63% were receiving stavudine (d4T) or zidovudine (AZT), 66% were on protease inhibitors, and median body mass index was 23 kg/m2. In a univariate GEE model, TZD was associated with an increase in limb fat mass (coeff = 0.14 kg vs placebo,P = .04). In a multivariable GEE model, patients receiving pioglitazone had significantly higher limb fat mass gains (coeff = 0.35 kg,P δ .01) compared to patients receiving placebo, while patients on rosiglitazone did not (coeff = 0.05 kg,P = .48). Interactions between thymidine analogue use and rosiglitazone and pioglitazone were not significant.Conclusions: In this meta-analysis, pioglitazone therapy was more effective than placebo to increase limb fat mass whereas rosiglitazone was not significantly better than placebo. The effectiveness of these drugs did not vary according to whether the patients were receiving thymidine analogues.

The biasing effect of clinical history on physical examination diagnostic accuracy

Medical Education 2011:45: 827–834

Reproducibility of DXA Estimations of Body Fat in HIV Lipodystrophy Implications for Clinical Research

Dual-energy X-ray absorptiometry (DXA) estimates of body fat are increasingly used for the evaluation of human immunodeficiency virus lipodystrophy (HIV LD); however, limited data are available on their reproducibility. This information is essential for using this tool as an end point in treatment trials or as a diagnostic tool. This study evaluates the reproducibility of DXA body fat estimation in HIV-positive subjects with and without lipodystrophy. Thirty subjects representing a spectrum of severity of fat redistribution underwent same-day repeat whole-body DXA scans (Hologic QDR 4500A scanner). Root mean square coefficients of variation (RMS-CV) were used to estimate minimum detectable differences (MDDs) for body fat content in different regions. Absolute MDD was calculated by multiplying the MDD by the mean fat-mass value for each anatomical area. The RMS-CV ranged from 4.0% for arm fat to 1.6% for total fat. Relative and absolute MDD values ranged from 11.0% or 160 g for arm fat to 4.3% or 628 g for total fat. DXA measurements of regional body fat mass in subjects with HIV show similar reproducibility to other populations. Minimal detectable differences were smaller than differences observed in published studies for all measurements. DXA is a sensitive tool for detecting changes in peripheral fat among patients with HIV lipodystrophy.

Should we teach using schemas? Evidence from a randomised trial

Medical Education 2012: 46: 815–822

Hypokalemia Following Polyethylene Glycol—Based Bowel Preparation for Colonoscopy in Older Hospitalized Patients with Significant Comorbidities

Background: Polyethylene glycol–based bowel preparations (PEGBPs) are widely perceived as safe and effective alternatives to oral sodium phosphate for bowel cleansing prior to colonoscopy. Most studies supporting this belief involve young patients with few comorbidities. Objective: To characterize the incidence of electrolyte disturbances following PEGBPs administered prior to colonoscopy among elderly inpatients and hypothesize that PEGBP would be associated with hypokalemia in this setting. Methods: This retrospective chart review, conducted at 3 tertiary care teaching hospitals in Toronto, Canada, from 2005 to 2007, included 96 consecutive patients aged 65 or older who were admitted to the hospital and given PEGBP prior to their first inpatient colonoscopy. Patients were excluded if they received additional cathartics, underwent colonoscopy while admitted to a critical care unit, or were admitted for a complication arising from an outpatient colonoscopy. The primary outcome was hypokalemia (serum potassium ≤3.2 mEq/L) within 48 hours of PEGBP. Results: Of 96 patients, 73 had serum electrolytes measured at baseline and within 48 hours following PEGBP administration. Hypokalemia was identified in 4 patients (5.5%) prior to PEGBP and in 15 patients (20.5%) after PEGBP (p < 0.001). The incidence of significant hypokalemia, defined as serum potassium ≤3.0 mEq/L, in this group was 9.6% (p = 0.008). We found consistent results among patients with and without concomitant diuretic treatment. Conclusions: Among older patients, administration of PEGBP is commonly complicated by the development of hypokalemia, which is occasionally severe. Monitoring of electrolytes may be necessary following colonoscopy, particularly in patients with cardiac or renal disease.

Role of clinical context in residents' physical examination diagnostic accuracy.

Medical Education 2011: 45: 415–421