Interpreting the results of patient reported outcome measures in clinical trials: the clinician's perspective.

This article deals with the problem of interpreting health-related quality of life (HRQL) outcomes in clinical trials. First, we will briefly describe how dichotomization and item response theory can facilitate interpretation. Based on examples from the medical literature for the interpretation of HRQL scores we will show that dichotomies may help clinicians understand information provided by HRQL instruments in RCTs.

Association between anemia and quality of life in a population sample of individuals with chronic obstructive pulmonary disease.

Background: Several studies investigated the association of anemia with health related quality of life (HRQL) in patients with chronic disease. However, there is little evidence regarding the association of anemia with HRQL in patients with chronic obstructive pulmonary disease (COPD).

Methods: This is a post-hoc analysis of a study which enrolled a population of adults aged 35-79 randomly selected from residents of Erie and Niagara Counties, NY, between 1996 and 2000.

Relative responsiveness of the Chronic Respiratory Questionnaire, St. Georges Respiratory Questionnaire and four other health-related quality of life instruments for patients with chronic lung disease.

Background: Selection of heath-related quality of life (HRQL) instruments that are most responsive to changes in HRQL prevents investigators from drawing false-negative conclusions about the effectiveness of an intervention. The objective of this study was to compare the responsiveness of the Chronic Respiratory Questionnaire (CRQ), the St. Georges Respiratory Questionnaire (SGRQ) and four other HRQL instruments.

EBM user and practitioner models for graduate medical education: what do residents prefer?

The objective of the study reported in this article was to assess and explain medical residents' preferences for the evidence based medicine (EBM) practitioner versus the EBM user models. A self-administered survey and focus group of residents attending a core curriculum EBM master session were undertaken. Most residents, particularly those earlier in their training, preferred the practitioner model.

Brief report: Internal medicine residents', attendings', and nurses' perceptions of the night float system.

Background: Residency training programs use the night float system increasingly to meet the new resident work hour regulations.

Objective: To assess and compare residents', attendings', and nurses' perceptions of the night float system.

Design: A survey study.

Misuse of baseline comparison tests and subgroup analyses in surgical trials.

It is unclear whether the misuse of statistical tests that compare patients' baseline characteristics and subgroup analyses in randomized controlled trials can be extrapolated to the surgical literature. We did an observational study evaluating the current use of baseline comparability tests and subgroup analyses in surgical randomized controlled trials. Published surgical randomized controlled trials in four medical journals were identified.

Pulmonary function and abdominal adiposity in the general population.

Background: The prevalence of obesity is increasing, and there is evidence that obesity, in particular abdominal obesity as a marker of insulin resistance, is negatively associated with pulmonary function. The mechanism for this association and the best marker of abdominal adiposity in relation to pulmonary function is not known.

Study Objective: We assessed the association between pulmonary function and weight, body mass index (BMI), waist circumference, waist/hip ratio, and abdominal height as markers of adiposity and body fat distribution.

Mortality predictions in the intensive care unit: comparing physicians with scoring systems.

Objective: Risk-prediction models offer potential advantages over physician predictions of outcomes in the intensive care unit (ICU). Our systematic review compared the accuracy of ICU physicians' and scoring system predictions of ICU or hospital mortality of critically ill adults.

Data Source: MEDLINE (1966-2005), CINAHL (1982-2005), Ovid Healthstar (1975-2004), EMBASE (1980-2005), SciSearch (1980-2005), PsychLit (1985-2004), the Cochrane Library (Issue 1, 2005), PubMed "related articles," personal files, abstract proceedings, and reference lists.

Can contraindications compromise evidence-based, patient-centered clinical practice?

Background: Despite their often weak evidence base, contraindications convey the unequivocally adverse risk-benefit profile of an intervention in a specific clinical context. However, some patients in that context may nonetheless prefer the contraindicated intervention (with its potential benefits and risks) to the available alternatives. The impact of contraindications on treatment decisions remains unexplored.

Addressing resource allocation issues in recommendations from clinical practice guideline panels: suggestions from an American College of Chest Physicians task force.

Most panels that develop clinical practice guidelines are poorly equipped to address resource allocation or cost issues associated with management options. This risks neglect, arbitrariness, lack of transparency, and methodological flaws in consideration of resource allocation. We provide recommendations for guideline panels to promote greater transparency and rigor.

Grading strength of recommendations and quality of evidence in clinical guidelines: report from an american college of chest physicians task force.

While grading the strength of recommendations and the quality of underlying evidence enhances the usefulness of clinical guidelines, the profusion of guideline grading systems undermines the value of the grading exercise. An American College of Chest Physicians (ACCP) task force formulated the criteria for a grading system to be utilized in all ACCP guidelines that included simplicity and transparency, explicitness of methodology, and consistency with current methodological approaches to the grading process. The working group examined currently available systems, and ultimately modified an approach formulated by the international GRADE group.

Do clinical marker states improve responsiveness and construct validity of the standard gamble and feeling thermometer: a randomized multi-center trial in patients with chronic respiratory disease.

Background: Optimizing the validity and responsiveness of utility measures will enhance their usefulness in randomized trials. We evaluated the impact of clinical marker state (CMS) rating prior to patients' rating their own health on two utility instruments (feeling thermometer (FT) and standard gamble (SG)) in patients with chronic respiratory disease (CRD).

Methods: We randomized 182 patients with CRD to complete the FT (self-administered) and SG with CMS (FT+/SG+, n=91) or without marker states (FT-/SG-, n=91) before and after undergoing respiratory rehabilitation in a multi-center trial.

Oxidative stress and pulmonary function in the general population.

Studies have shown increased oxidative stress in patients with chronic airflow limitation; however, the population-based evidence for the association of oxidative stress with pulmonary function is limited. The authors analyzed the association of plasma thiobarbituric acid-reactive substances (TBARS), glutathione, glutathione peroxidase, and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox)-equivalent antioxidant capacity with forced expiratory volume in 1 second and forced vital capacity using data collected from 1996 to 2000 in a general population sample from western New York State (n = 2,346). After adjustment for covariates including smoking status, lifetime pack-years of smoking, education, weight, and eosinophils, multivariate analysis showed an inverse association of TBARS with forced expiratory volume in 1 second and forced vital capacity as the percentage of the predicted value (FEV1% and FVC%, respectively), positive associations of glutathione peroxidase with FEV1% and FVC%, and an inverse association of glutathione with FEV1% in men (p < 0.

Randomized trials stopped early for benefit: a systematic review.

Context: Randomized clinical trials (RCTs) that stop earlier than planned because of apparent benefit often receive great attention and affect clinical practice. Their prevalence, the magnitude and plausibility of their treatment effects, and the extent to which they report information about how investigators decided to stop early are, however, unknown.

Objective: To evaluate the epidemiology and reporting quality of RCTs involving interventions stopped early for benefit.

Is being breastfed as an infant associated with adult pulmonary function?

Objective: Breastfeeding reduces the risk of asthma and respiratory infections in infants. Since respiratory infections are associated with reduced pulmonary function in adolescents, pulmonary function impairment may be carried into adulthood. Our aim was to determine whether a history of having been breastfed as an infant is a determinant of adult pulmonary function.

The impact of illness in patients with moderate to severe gastro-esophageal reflux disease.

Background: Gastro-esophageal reflux disease (GERD) is a common disease. It impairs health related quality of life (HRQL). However, the impact on utility scores and work productivity in patients with moderate to severe GERD is not well known.

Internal consistency reliability is a poor predictor of responsiveness.

Background: Whether responsiveness represents a measurement property of health-related quality of life (HRQL) instruments that is distinct from reliability and validity is an issue of debate. We addressed the claims of a recent study, which suggested that investigators could rely on internal consistency to reflect instrument responsiveness.

Methods: 516 patients with chronic obstructive pulmonary disease or knee injury participating in four longitudinal studies completed generic and disease-specific HRQL questionnaires before and after an intervention that impacted on HRQL.

Electronic mail was not better than postal mail for surveying residents and faculty.

Objective: To compare response rate, time to response, and data quality of electronic and postal surveys in the setting of postgraduate medical education.

Study Design And Setting: A randomized controlled trial in a university-based internal medicine residency program. We randomized 119 residents and 83 faculty to an electronic versus a postal survey with up to two reminders and measured response rate, time to response, and data quality.