A randomised controlled trial evaluating the effects of two workstation interventions on upper body pain and incident musculoskeletal disorders among computer operators.

BACKGROUND: Call centre work with computers is associated with increased rates of upper body pain and musculoskeletal disorders. METHODS: This one year, randomised controlled intervention trial evaluated the effects of a wide forearm support surface and a trackball on upper body pain severity and incident musculoskeletal disorders among 182 call centre operators at a large healthcare company. Participants were randomised to receive (1) ergonomics training only, (2) training plus a trackball, (3) training plus a forearm support, or (4) training plus a trackball and forearm support. Outcome measures were weekly pain severity scores and diagnosis of incident musculoskeletal disorder in the upper extremities or the neck/shoulder region based on physical examination performed by a physician blinded to intervention. Analyses using Cox proportional hazard models and linear regression models adjusted for demographic factors, baseline pain levels, and psychosocial job factors. RESULTS: Post-intervention, 63 participants were diagnosed with one or more incident musculoskeletal disorders. Hazard rate ratios showed a protective effect of the armboard for neck/shoulder disorders (HR = 0.49, 95% CI 0.24 to 0.97) after adjusting for baseline pain levels and demographic and psychosocial factors. The armboard also significantly reduced neck/shoulder pain (p = 0.01) and right upper extremity pain (p = 0.002) in comparison to the control group. A return-on-investment model predicted a full return of armboard and installation costs within 10.6 months. CONCLUSION: Providing a large forearm support combined with ergonomic training is an effective intervention to prevent upper body musculoskeletal disorders and reduce upper body pain associated with computer work among call centre employees.

The relative contributions of lean tissue mass and fat mass to bone density in young women.

Although obesity is associated with increased risk of many chronic diseases including cardiovascular disease, diabetes, hypertension, and cancer, there is little evidence to suggest that obesity increases risk of osteoporosis. In fact, both weight and body mass index (BMI) are positive predictors of bone mass in adults, suggesting that those who are overweight or obese may be at lower risk of osteoporosis. However, recent evidence suggests that in children and adolescents, obesity may be associated with lower rather than higher bone mass. To understand the relation of fat mass to bone mass, we examined data gathered from an ethnically diverse group of 921 young women, aged 20-25 years (317 African Americans, 154 Asians, 322 Caucasians, and 128 Latinas) to determine how fat mass (FM) as well as lean tissue mass (LTM) is associated with bone mass. Bone mass, FM, and LTM were measured using dual energy X-ray absorptiometry (GE Lunar Corp, Madison, WI). Bone mass was expressed as bone mineral density (BMD; g/cm2) and bone mineral apparent density (BMAD; g/cm3) for the spine and femoral neck, and as BMD and bone mineral content (BMC; g) for the whole body. Regression techniques were used to examine the following: (1) in separate equations, the associations of LTM and FM with each bone mass parameter; and (2) in the same equation, the independent contributions of LTM and FM to bone mass. LTM and FM were positively correlated with BMD at all skeletal sites. When the contributions of FM and LTM were examined simultaneously, both FM and LTM continued to be positively associated with bone mass parameters but the effect of FM was noted to be smaller than that of LTM. We conclude that in young women, LTM has a greater effect than fat mass on bone density per kg of tissue mass.

Which plasma antioxidants are most related to fruit and vegetable consumption?

Substantial evidence suggests that fruit and vegetable intake reduces the risk of some cancers and other chronic diseases. While a varied diet containing fruits and vegetables may confer benefits greater than those of any single nutrient, it would be useful to have data on the plasma nutrients most influenced by fruit and vegetable intake. The authors examined the correlation between fruit and vegetable intake as measured by the abbreviated CLUE II food frequency questionnaire and several plasma antioxidants. This study includes 116 male subjects aged 35-72 years who were nonsmokers and nonusers of vitamin supplements and who provided blood samples in the CLUE II Study in Washington County, Maryland. Plasma was assayed for ascorbic acid, beta-carotene, beta-cryptoxanthin, and alpha- and gamma-tocopherol. Lipid- and energy-adjusted partial correlation for the relation with fruit and vegetable intake was r = 0.64 for ascorbic acid, r = 0.44 for beta-carotene, and r = 0.50 for beta-cryptoxanthin. While this study does not address efficacy, the stronger association of ascorbic acid with fruit and vegetable intake seen here may imply that ascorbic acid is an important component of the protective effect seen for fruits and vegetables in numerous epidemiologic studies.

Nutritional and health status of Tibetan children living at high altitudes.

BACKGROUND: Children living at high altitudes often have delayed growth, but whether growth retardation is related to altitude or to other factors is not known. METHODS: A multicultural health care team assessed 2078 Tibetan children 0 to 84 months of age for anthropometric and clinical signs of malnutrition. The children lived in 11 counties, which contained more than 50 diverse urban and nonurban (nomadic, agricultural, or periurban) communities in the Tibet Autonomous Region of China. The height and weight of the children were compared with those of U.S. children. Height and weight were expressed as z scores (the number of standard deviations from the median of the age- and sex-specific reference group). RESULTS: The mean z score for height fell from -0.5 to -1.6 in the first 12 months of life and generally ranged from -2.0 to -2.4 in older children. Overall, of 2078 children, 1067 (51 percent) had moderately or severely stunted growth, as defined by a z score of -2.0 or lower. Of the 1556 children 24 months of age or older, 871 (56 percent) had stunted growth, which was severe (z score, -3.0 or lower) in 380 (24 percent). Among the children in this age group, 787 of the 1313 nonurban children (60 percent) had stunting, as compared with 84 of the 243 urban children (35 percent). Stunting was associated with clinical conditions such as rickets, abdominal distention, hair depigmentation, and skin lesions and with a maternal history of hepatitis or goiter. Stunting was not associated with altitude, after adjustment for the type of community. CONCLUSIONS: In Tibetan children, severe stunting due to malnutrition occurs early in life, and morbidity is high.

Effect of keyboard keyswitch design on hand pain.

This randomized clinical trial evaluated the effects of keyboard keyswitch design on computer users with hand paresthesias. Twenty computer users were matched and randomly assigned to keyboard A (n = 10) or B (n = 10). The keyboards were of conventional layout and differed in keyswitch design. Various outcome measures were assessed during the 12 weeks of use. Subjects assigned keyboard A experienced a decrease in hand pain between weeks 6 and 12 when compared with keyboard B subjects (P = 0.05) and demonstrated an improvement in the Phalen test time (right hand, P = 0.006; left hand, P = 0.06). Keyboard assignment had no significant effect on change in hand function or median nerve latency. We conclude that use of keyboard A for 12 weeks led to a reduction in hand pain and an improved physical examination finding when compared with keyboard B. There was no corresponding improvement in hand function or median nerve latency.

Influence of pre-adolescent diet on quantitative ultrasound measurements of the calcaneus in young adult women.

Nongenetic determinants of quantitative ultrasound (QUS) properties of the bone remain to be identified. The purpose of this study was to determine relationships between early adolescent diet and QUS bone measurements taken in young adulthood. Subjects were participants in the 10-year longitudinal National Heart, Lung, and Blood Institute Growth and Health Study (NGHS). QUS parameters measured at the calcaneus in a convenience subsample of 63 18- to 19-year-old black and white women were correlated with dietary data collected when the subjects were aged 9-11 years. We hypothesized that pre-adolescent intake of calcium, magnesium, vitamin C and protein, nutrients known to be associated with bone development, would be associated with QUS measurements in young women. Stepwise multiple regression analysis, controlling for race, height and weight, demonstrated that pre-adolescent intake of calcium and magnesium were positively related to QUS parameters (calcium with broadband ultrasound attenuation, and magnesium with speed of sound and bone velocity). Our findings suggest that pre-adolescent diet may be associated with bone properties as measured by ultrasound. Further investigations of this relationship may yield a deeper understanding of the impact of diet on skeletal development. The small size of the convenience sample used for the analysis precludes stronger inferences at this time.

Evaluating an AIDS sexual risk reduction program for young adults in public night schools in São Paulo, Brazil.

OBJECTIVES: To describe sexual risk for HIV infection among adult night school students in São Paulo, Brazil, and to evaluate the effect of an HIV/AIDS prevention workshop to reduce sexual risk. SUBJECTS AND METHODS: A longitudinal study was conducted among four demographically similar public night schools in the inner city of São Paulo. Schools were randomized into intervention and control conditions. Of 394 young adults who took part in the baseline survey, 304 (77%) completed a postintervention questionnaire. INTERVENTIONS: In a workshop consisting of four sessions of 3 h each, the students discussed AIDS symbolism, the impact of AIDS on their lives, risk perception, the way in which sexual norms shape knowledge and attitudes, AIDS-related knowledge, reproduction and sexual pleasure, and condom use negotiation. We fostered community-building through AIDS training courses for teachers in the schools, peer support programs and public events. RESULTS: At baseline, 87% had been sexually active at some time and 76% had had sex in the past 6 months. Among those who reported vaginal intercourse and/or anal intercourse, condom use was low. The workshops were positively process-evaluated and supported by the community, the students, their teachers and their parents. We obtained statistically significant effects from the workshops for females only, who reported improved communication with partners about sex and AIDS and less unprotected sex with non-monogamous partners after the intervention. CONCLUSION: These data show that the sexual risk of HIV infection can be lowered when Brazilian disenfranchized communities support AIDS prevention workshops. Even more impressive results may be achieved if the need to address socioeconomic obstacles and gendered sexual roles is emphasized through further long-term community development programs.

Intestinal cell respiration is influenced by animal age, strain, and feeding status.

The objectives of this study were to evaluate the influence of aging and the fasted vs fed state on substrate oxidation by jejunal and colonic cells in vitro, and to determine whether the effects of these factors would be influenced by rat strain. Young (4 mo) and aged (24 mo) male rats of the Fischer 344 (F344) and Fischer x Brown Norway (F x BN) strains were used either following a 48-hr fast or in the ad libitum fed state. On the morning of experimentation, cells were removed from segments of the jejunum and colon and aliquots of these suspensions were incubated in 5 mM concentrations of substrates containing trace quantities of 14C-labeled isotopes. Following 60 min of incubation, 14CO2 was collected and quantified to determine substrate oxidation. The oxidation of glucose, glutamine, and 3-hydroxybutyrate was studied in jejunal and colonic cells, and the oxidation of acetate and butyrate was studied in colonic cells only. Glucose oxidation by jejunal cells was lower when cells were taken from 48-hr fasted animals than from fed animals, but the feeding status of the animal did not significantly influence oxidation of other substrates by jejunal or colonic cells. Substrate oxidation was not different for the F344 vs F x BN strains when jejunal and colonic cells were taken from young animals. Differences due to rat strain became apparent in the aged animals, however, with oxidation of several substrates being higher for the aged F344 than for the aged F x BN animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Demographic and economic factors associated with dietary quality for adults in the 1987-88 Nationwide Food Consumption Survey.

Data for 5,884 adults (19 years of age and older) who participated in the 1987-88 Nationwide Food Consumption Survey (1987-88 NFCS) were used to investigate demographic and economic factors associated with dietary quality. Although the low response rate for the 1987-88 NFCS has raised concerns about possible bias, it is appropriate to use this extensive data set for analyses that do not attempt to generalize the results to the US population as a whole. Two aspects of quality were calculated for the mean of the 3-day reported intakes: number of nutrients below two thirds of the 1989 Recommended Dietary Allowance (RDA) (low-intake nutrients) and percent of energy from fat. Few adults reported mean intakes that met suggested guidelines: 22% of diets were above two thirds of the RDA for all 15 nutrients and 14% were below 30% fat, but only 2% met both criteria. Energy intake was a strong negative predictor of number of low-intake nutrients and a weak positive predictor of percent of energy from fat. Results of multivariate regression analyses identified few demographic or economic predictors of either the number of low-intake nutrients or percent of energy from fat. According to these data, diets of most adults do not conform to current dietary guidelines. Nutrition education efforts should be directed to all adults, and research should be undertaken to determine more effective ways to help adults improve their overall dietary quality.

A study of the effect of perchloroethylene exposure on the reproductive outcomes of wives of dry-cleaning workers.

The purpose of this investigation was to compare the reproductive outcomes of wives of men exposed to perchloroethylene in the dry-cleaning industry compared to those of wives of laundry workers. Seventeen female partners of dry cleaners and 32 partners of laundry workers were interviewed. The number of pregnancies and the standardized fertility ratios were similar between the two groups. Wives of dry cleaners did not have higher rates of spontaneous abortions. However, wives of dry cleaners were more than twice as likely to have a history of attempting to become pregnant for more than 12 months or to have sought care for an infertility problem. Cox proportional hazards models indicated that dry-cleaners' wives had half of the per-cycle pregnancy rate of wives of laundry workers, when controlling for other potential confounders (estimated rate ratio of 0.54, 95% C.I. = 0.23, 1.27).

A study of the effect of perchloroethylene exposure on semen quality in dry cleaning workers.

The purpose of this investigation was to determine the effects of perchloroethylene (PCE) exposure on human semen quality. We compared the semen quality of 34 dry cleaners with that of 48 laundry workers. We examined the relationships of 17 semen parameters to expired air levels of PCE and to an index of exposure based on job tasks in the last three months. The average sperm concentration was over 80 million for both dry cleaners and laundry workers, but approximately one-quarter of each group was oligospermic. The overall percentage of abnormal forms was similar for the two groups; however, sperm of dry cleaners were significantly more likely to be round (t = -3.29, p = 0.002) and less likely to be narrow (t = 2.35, p = 0.02) than the sperm of laundry workers. These effects were dose-related to expired air levels and to the exposure index after controlling for potential confounders (e.g., heat exposure). The average percent motile sperm for both groups was slightly over 60%; however, sperm of dry cleaners tended to swim with greater amplitude of lateral head displacement (ALH) than those of laundry workers (t = -1.73, p = 0.09), and level of PCE in expired air was a significant predictor of ALH in the multiple regression model (t = 2.00, p = 0.05). In addition, exposure index was a significant negative predictor of the sperm linearity parameter (t = -2.57, p = 0.01). These results suggest that occupational exposures to PCE can have subtle effects on sperm quality. Additional analyses are required to determine whether these effects are associated with changes in fertility.

Generational differences in perinatal health among the Mexican American population: findings from HHANES 1982-84.

Data from the Hispanic Health and Nutrition Examination Survey (HHANES) were used to examine a profile of social, medical, and behavioral characteristics associated with low birth-weight (LBW) and miscarriages in first and second generation Hispanics of Mexican descent. The percentage of LBW was 5.3 and of miscarriages was 12.7. LBW rates were higher for second generation primipara and multipara compared with first generation women. Using multivariate logistic regression techniques and adjusting for complex design effects, generation was found to be a significant predictor of LBW but not of miscarriages. The findings support existing evidence that a Mexican cultural orientation protects first generation. Mexico-born women against a risk for LBW. However, the findings do not show significant effects of generation on miscarriages, suggesting that cultural effects are not consistent for all pregnancy outcomes. Furthermore, we suggest that the higher rates of LBW in second generation women are not due to a higher rate of miscarriages as has been hypothesized.

Personal goals of recently divorced women.

This paper is a report of the synthesis of feminism and science in a study of the personal goals of recently divorced women with children. The divorce records of three counties were used to identify the participants; eight categories described the primary goals identified by 250 women. Independence, followed by employment and education were the most frequently cited categories. Analysis of variance was computed to analyze the relationships among the primary goal categories, the personal characteristics of the women and their feminist attitudes. Age was the only variable related to selection of a primary goal. Older women chose employment and environmental goals more often than they did mental health goals.

Improving recovery following cardiac surgery: a randomized clinical trial.

To enhance individual and family health during recovery from heart surgery, this study employed nursing interventions based on self-efficacy and family stress theory during the hospitalization period and for 3 months thereafter. The effectiveness of the interventions were assessed through a randomized trial in which 67 prospective bypass and valve surgery patients, aged 30-77 years, and their spouses, were allocated either the experimental interventions or usual care and followed for 6 months. At 3 months post-surgery, the only statistically significant differences between the experimentals and controls were on perceived self-efficacy for lifting and tolerating emotional distress. At 6 months no significant differences were found on individual or family measures. Analyses revealed that age, gender and preoperative cardiac status significantly affected individual recovery. The study is continuing with a larger sample in order to explicate the recovery process and to better determine whether a low intensity nursing intervention can effect changes in individual and family recovery.

The sensations of pulmonary dyspnea.

This study compared recalled physical and emotional sensations during episodes of acute dyspnea across pulmonary disease groups. The convenience sample consisted of 68 subjects with emphysema-bronchitis, asthma, vascular, and restrictive disease. Temporal patterns of physical and emotional sensations before and during episodes of dyspnea were identified. The frequency of sensations was remarkably similar across disease categories with few significant differences identified. Rather than the disease category, the frequency, intensity, and periodicity of the symptom of dyspnea had the greatest effect on the quality and frequency of sensations reported. The intensity of usual dyspnea reported on a visual analog scale varied significantly among groups, p = .026, with asthmatics having the lowest mean score and vascular subjects the highest. Females reported significantly greater usual dyspnea than males, p = .005. The variables of pulmonary disease group, gender, fatigue, and total network of social support were significantly related to usual dyspnea, and pulmonary group, gender, and attendance at Better Breathers classes were significantly related to worst dyspnea.

Appraisal of values in the choice of treatment.

The Gortner Values in the Choice of Treatment Inventory is a set of declarative statements to which respondents can indicate agreement or disagreement in a Likert-type format. The statements are based on the moral principles of Autonomy, Beneficence/Nonmaleficence, and Justice as conceptualized by Beauchamp and Childress (1979). The first trial was reported for 15 families in 1980. The second trial was part of a larger study in June 1981 to April 1982 of 100 families, of whom 70 had a member undergoing coronary artery bypass surgery, and 30 had a member under medical treatment for coronary artery disease. Spearman rank order correlations were used to evaluate responses within families and between groups at Time 1 and Time 2. Surgical family correlations for Autonomy were weak, but were moderately strong for Beneficence/Nonmaleficence. A highly significant main-effect finding, using repeated measures ANOVA, was that all patients and spouses showed mean Autonomy scores that were significantly higher than those for Beneficence/Nonmaleficence and Justice. Principal components factor analysis followed by varimax rotation supported two of the three hypothesized constructs. Surgical families emerged as the key reference group for further analysis.