Development and validation of a questionnaire for preliminary assessment of heat stress at workplace

Background: Current heat stress indices are not completely suitable for heat strain screening in developing countries due to their inherent and applied limitations. The aim of this study was development of a questionnaire method entitled "Heat Strain Score Index" [HSSI] in order to perform a preliminary assessment of heat stress at work

Methods: This research included six phases [i] Item generation [ii] Content validity [iii] Reliability analysis [iv]Structure validity [v] Concurrent validity and [vi] Classification of thermal risk level. In item generation phase, 40 items were identified to have impact on the heat strain. Content validity was evaluated by occupational health specialists

Results: In consistency assessment, Cronbach's coefficient [alpha] of items was 0.91. Exploratory factor analysis on items HSSI draft identified four subscales which explained 71.6% of the variance. Correlation between the HSSI score with aural temperature was 0.73. Cut-off point; sensitivity and specificity for upper no thermal strain zone were 13.5, 91% and 50%, respectively. Whereas Cut-off point, sensitivity and specificity for lower thermal strain zone were 18, 86% and 73%

Conclusions: The results showed that 18 variables that were measurable through subjective judgment and observation in the HSSI scale covered heat stress key factors. This scale demonstrated reliability and initial validity in scale were suitable. Therefore HSSI scale for primary evaluation heat stress is appropriate

Child weight growth trajectory and its determinants in a sample of Iranian children from birth until 2 years of age

Growth is one of the most important indices in child health. The best and most effective way to investigate child health is measuring the physical growth indices such as weight, height and head circumference. Among these measures, weight growth is the simplest and the most effective way to determine child growth status. Weight trend at a given age is the result of cumulative growth experience, whereas growth velocity represents what is happening at the time. This longitudinal study was conducted among 606 children repeatedly measured from birth until 2 years of age. We used linear mixed model to analyze repeated measures and to determine factors affecting the growth trajectory. LOWESS smooth curve was used to draw velocity curves. Gender, child rank, birth status and feeding mode had a significant effect on weight trajectory. Boys had higher weight during the study. Infants with exclusive breast feeding had higher weight than other infants. Boys had higher growth velocity up to age 6 month. Breast fed infants had higher growth velocity up to 6 month, but thereafter the velocity was higher in other infants. Many of the studies have investigated child growth, but most of them used cross-sectional design. In this study, we used longitudinal method to determine effective factors on weight trend in children from birth until 2-year-old. The effects of perinatal factors on further growth should be considered for prevention of growth disorders and their late complications

study of factor structure of the mood disorder questionnaire in a sample of Iranian pregnant women

The Mood Disorder Questionnaire [MDQ] has been developed as a self-reporting, brief, and easy-to-use screening instrument to improve identification of bipolar mood disorders. The goals of the present study were to examine the prevalence of this disorder and interrelationship of its symptoms by factor analysis of MDQ in a group of pregnant women in Iran. One thousand and eight hundred and ninety eight pregnant women in their third trimester were recruited to take part in a cross-sectional study. Trained local health workers administered MDQ for them. A principal component factor analysis was used to determine factors for relevant items of MDQ questions. The mean age of the participants was 25.4 +/- 5.1 years. About 3.9% of participants met the MDQ diagnostic criteria for bipolar mood disorder, and 19.6% scored positively for at least one Mood Disorder Questionnaire item and also had moderate to severe psychosocial impairment [second sample]. The first factor analysis on the whole sample revealed elevated mood, increased self-confidence and energy, increased social activity and disinhibited sexual behavior as significant. Irritability, talkativeness, insomnia, racing thoughts, distractibility, risky behavior and overspending were determined as important by the second factor analysis. Self-reporting of hypomanic symptoms by Iranian pregnant women revealed a relatively high prevalence rate of Bipolar Spectrum Disorders. Study analysis also showed there were two independent factors: an energized-activity factor and an elevated mood-thought racing factor