The objective of this study was to identify risk factors for work disability among persons with carpal tunnel syndrome (CTS). The study was designed to analyze data from the Occupational Health Supplement of the National Health Interview Survey, a nationwide, population-based survey. Subjects included 544 survey respondents with self-report of CTS and 32,688 survey respondents without CTS, all aged 18-64 years, and with a history of labor force participation. Measurements were as follows: Dependent variables were work disability, defined either as cessation of employment without attribution of cause or, alternatively, as cessation of employment or job change specifically attributed to CTS by the survey respondent. Independent variables were ergonomic risk of work disability, defined by minutes of workplace repetitive hand and wrist bending for the most recent job held. This measure was derived from responses categorized by an occupation and industry matrix independent of CTS status. Socio-demographic and health status risk factors for work disability were based on the respondent report. The main results were as follows: Among 544 persons with CTS, 58 (11%, CI 8-13%) reported work disability specifically attributed to CTS, representing an estimated national prevalence of 240,578 persons with this limitation. Workplace ergonomic risk, measured as repetitive hand or wrist bending in the occupation and industry of last employment, was a significant factor predictive of CTS-attributed work disability (per 120 min of daily exposure, OR 1.7, CI 1.1-2.6), even after taking into account socio-demographic factors and health status. The conclusions were that work disability among persons with CTS is common. For those with CTS, working conditions characterized by repetitive bending of the hand or wrist may increase the risk of work disability associated with this condition.

To examine whether diffuse pleural thickening (DPT) causes impairment of pulmonary function independent of other manifestations of asbestos-related disease, we studied individuals selected from 1,150 men with occupational asbestos exposure who had undergone pulmonary function testing and computed tomographic (CT) scanning. The CT scans revealed 84 subjects with DPT as defined for CT. Of these 84 subjects, 53 eligible study cases were matched by age with a referent group without DPT from the same exposed group. No difference was demonstrated between cases and referents in smoking history, length of exposure, latency, or the proportion with either interstitial fibrosis or pleural plaques. Individuals with DPT demonstrated significantly reduced forced vital capacity (FVC) (p = 0.002) and diffusing capacity for carbon monoxide (DLCO) (p = 0.002) as compared with the referents. No difference was found in the two groups' FEV1 to FVC ratio (FEV1/FVC). Individuals with DPT and either interstitial fibrosis or pleural plaques showed a significantly lower FVC than did those with fibrosis or pleural plaques alone. Individuals with DPT and rounded atelectasis had similar pulmonary function to those with DPT and no rounded atelectasis. Subjects with DPT had a more frequent history of coronary bypass surgery than referents (19% versus 2%; p = 0.008). We conclude that subjects with DPT have restrictive pulmonary function and reduced diffusing capacity independent of other manifestations of asbestos-related disease.

The aim of this study was to determine the dose-response relationship between cigarette smoke exposure and pulmonary cell and cytokine concentrations in bronchoalveolar lavage (BAL). BAL cells and BAL supernatant concentrations of tumour necrosis factor-alpha (TNF alpha), interleukin (IL)-1 beta, IL-6, IL-8, and monocyte chemoattractant protein (MCP)-1 from 14 healthy smokers and 16 healthy nonsmokers were quantified. Statistically greater concentrations of neutrophils, macrophages, IL-1 beta, IL-6, IL-8 and MCP-1 were observed among smokers compared with nonsmokers (p < or = 0.0007 in all cases). Cigarette smoking, categorized ordinally as: less than one pack, one pack, or greater than one pack per day, was predictive of BAL macrophages (p < 0.0001), neutrophils (p = 0.015), IL-1 beta (p < 0.001) and IL-8 (p = 0.02). We conclude that concentrations of macrophages, neutrophils, IL-1 beta and IL-8 are elevated in the pulmonary microenvironment of smokers in a cigarette dose-dependent manner. Based on the present findings, we would caution against simple analyses that treat current smokers as a homogeneous group and which do not account for smoking intensity.

Psychological factors can play a role in asthma symptoms and may play a role in how individuals manage asthma. Because poor self-management of asthma has been linked to poor outcomes, it is important to understand perceived control of asthma--the individual's perceived ability to deal with asthma and its exacerbations effectively. This study used data from an ongoing panel study of adults with asthma (n = 601). The 11-item Perceived Control of Asthma Questionnaire (PCAQ) demonstrated internal consistency (Cronbach's alpha = 0.74) and excellent construct validity, correlating strongly with asthma severity, quality of life, and Medical Outcomes Study Short Form (SF-36) measures of health status (p < 0.05). After controlling for demographics and asthma severity, each 6-point decrement in PCAQ score was significantly associated with increased risk of hospitalization (OR = 1.4 [95% CI: 1.1 to 1.8]), frequent activity restriction (OR = 1.5 [1.2 to 1.8]), and, among those with labor force participation (n = 551), asthma-related cessation of employment (OR = 1.7 [1.1 to 2.4]). The PCAQ is a short, easy to administer, reliable, and valid measure of perceived control of asthma. It is strongly associated with adverse asthma outcomes even taking into account demographic characteristics and asthma severity, suggesting that patient-centered interventions focusing on perceived control might improve asthma outcomes.

STUDY HYPOTHESIS

Physicians may consult references such as Physicians' Desk Reference (PDR) for overdose management advice. Although PDR recommendations are approved by the US Food and Drug Administration (FDA), we hypothesized that they are often outdated and potentially hazardous.

METHODS

We surveyed physicians who consulted our poison center during a 1-month period with regard to their use of the PDR for overdose information and also compared PDR overdose treatment recommendations with those of five current major toxicology references. For the PDR overdose information review we examined data from the American Association of Poison Control Centers to identify pharmaceutical categories with the largest number of deaths. We reviewed the four leading drugs with at least 1,000 reported exposures in each category and identified 20 PDR-listed brand-name products for analysis. We obtained the consensus from five current toxicology references on contraindicated treatments, ineffective treatments, and specific recommended treatments or antidotes. Finally, we compared the overdose management advice provided in the 1994 PDR with the toxicology reference consensus.

RESULTS

Forty of 80 of physicians surveyed (50%) reported use of the PDR for overdose information in the preceding 12 months. Of the 20 PDR entries, 16 (80%) had at least one deficiency, and 5 (25%) had two or more deficiencies. Thirteen (65%) omitted an indicated specific treatment, three (15%) recommended contraindicated treatments, and four (20%) advised ineffective treatments with potential for harm. Only four entries (20%) had no deficiencies by our survey criteria.

CONCLUSION

We found serious discrepancies in overdose treatment advice in the PDR compared with a consensus of current toxicology references. Altogether, four of five PDR entries were deficient, and almost half advised ineffective or frankly contraindicated therapies. Despite FDA approval, the use of PDR overdose advice in a serious poisoning case could result in unnecessary morbidity or mortality.

The association between serum beta-carotene or retinol concentration and level of ventilatory function was investigated in a population of asbestos-exposed men with a high rate of current and former cigarette smoking. The study population consisted of 816 subjects enrolled in the pilot component of the Carotene and Retinol Efficacy Trial (CARET), a placebo-controlled trial of supplemental beta-carotene and retinyl palmitate for the chemoprevention of lung cancer. Data available for analysis included baseline questionnaire, spirometry, chest X-ray, food frequency questionnaire, and serum beta-carotene and retinol concentrations. Serum beta-carotene concentration was associated with FEV1 (p < 0.05) and FVC (p < 0.05), with an approximately 100-ml increase over predicted values associated with raising the serum concentration from the 25th to the 75th percentile of the distribution in the study population (absolute difference = 155 ng/ml), even after adjustment for the confounding effects of asbestos exposure and cigarette smoking. Raising the serum retinol concentration from the 25th to the 75th percentile (absolute difference = 211 ng/ml) was associated with an approximately 70 ml increase in FVC (p < 0.05) over the predicted value. These results provide support for the hypothesis that beta-carotene and retinol have a protective effect on loss of ventilatory function.

Organic Dust Toxic Syndrome (ODTS) is a flu-like syndrome that can occur after inhalation of cotton, grain, wood chip dusts, or other organic dusts or aerosols. We investigated whether inflammatory pulmonary responses occur, even after relatively brief, low-level wood chip mulch exposure. Six volunteers were exposed to wood chip mulch dust. Total dust and/or endotoxin levels were measured in five subjects. Pulmonary function and peripheral blood counts were measured before and after exposure in each subject. Bronchoalveolar lavage (BAL) was performed in each subject after exposure, and cell, cytokine, and protein concentrations were measured. Control BAL without previous exposure was also performed on three of the subjects. Three of six subjects had symptoms consistent with ODTS. No clinically relevant or statistically significant changes in pulmonary function tests after exposure were found. Three subjects manifested a marked elevation in neutrophil percentage in their BAL (range, 10 to 57%). When these three subjects underwent control BAL, the postexposure comparison demonstrated an increase in neutrophil levels of 154 +/- 89 x 10(3)/mL (mean +/- standard error; P = 0.22). The mean increase in BAL interleukin-8 levels after exposure, compared with paired control values, was 11.2 +/- SE 2.5 pg/mL (P = 0.047). There was also an increase in BAL interleukin-6 levels that reached borderline significance (6.4 +/- SE 2.0 pg/mL; P = 0.08). Tumor necrosis factor levels were increased in all three subjects' BAL as well (0.4 +/- SE 0.2 pg/mL), but this change was not statistically significant (P = 0.2). Our findings of increased BAL proinflammatory cytokine and neutrophil levels are consistent with the theory that cytokine networking in the lung may mediate ODTS.