Understanding prognosis to improve rehabilitation: the example of lateral elbow pain.

OBJECTIVE: A systematic overview of evidence aimed at determining the clinical course of lateral elbow pain and prognostic factors that affect elbow pain duration and outcomes. DATA SOURCES: Online bibliographic database searches from 1983 to 1994; information requests from selected authors and bibliography screenings. STUDY SELECTION: One author reviewed 424 articles; 40 met the following eligibility criteria: any study with primary data on soft tissue injuries specific to the elbow which referred to prognosis or reported use of any outcome measure. DATA ABSTRACTION: Strength of evidence grade based on clinical epidemiological validity assessment. Criteria included in the validity assessment included case definition, patient selection, follow-up, outcome, prognostic factors, and analysis. All eligible studies were independently assessed by two investigators. DATA SYNTHESIS: Four studies (10%) were judged to provide moderate strength of evidence; no studies were graded as providing strong evidence on prognosis. All four moderate-quality studies were clinical trials of short duration. One study indicated that site of lesion and prior occurrence may be predictive of poorer outcome in patients with lateral epicondylitis. CONCLUSION: The majority of studies on lateral elbow pain were limited by methodological weaknesses in selection and definition of the study population, length of follow-up, and analysis of prognostic factors. Estimates of duration were only available from weaker studies with longer follow-up times; significant subject heterogeneity in the weaker studies prevented a determination of usual clinical course. More methodologically rigorous research on prognosis could assist clinicians in patient care and evaluation of interventions.

Use of noseclips in pulmonary function tests.

Spirometry was performed on 136 male industrial workers experienced in undergoing pulmonary function testing for the purpose of studying the effects of the use of noseclips on forced vital capacity (FVC) maneuvers. A cross-over design was employed with each subject serving as his own reference. Forced expiratory volume in 1 second (FEV1) and FVC measurements were recorded adhering closely to the guidelines set down by the American Thoracic Society. Assuming that a 30-ml difference in FVC and FEV1 is not important, we conclude that these measurements are not significantly affected by the use of noseclips. However, trial order was found to affect the outcome. The FVC and FEV1 values on the first trial were consistently lower than those on the second regardless of noseclip use. Many subjects experienced discomfort from noseclips and their use is not recommended for routine purposes.

A pragmatic approach to standard setting--the example of coal tar products and asphalt.

This article will outline a pragmatic approach directed to incorporating key elements of a scientific review of the literature and derive a proposal for an occupational exposure standard for coal tar, coal tar pitch, creosote, petroleum pitch, bitumen and asphalt, six substances which contain polynuclear aromatic hydrocarbons. Five approaches to the standard setting process are reviewed and their strengths and weaknesses discussed. Unfortunately there does not exist an acceptable epidemiological data set, other than the coke oven emission studies, on which to base a valid and reliable risk assessment model. Based on comparative potency experiments of complex mixtures, consideration of the state-of-the-art sampling and analytical methods, prevention of acute human health effects, and current existing standards for these substances throughout the world, a set of recommended exposure standards are derived for health policy makers.