Occupational Health and Well-being Questionnaire (OHWQ): an instrument to assess psychosocial risk and protective factors in the workplace.

OBJECTIVES: Psychosocial stressors at work have been identified as significant risk factors for several mental and physical health problems. These stressors must be compensated by psychosocial resources to prevent or reduce adverse effects on health. Questionnaires measuring these stressors and resources already exist, but none integrate digital stress, ethical culture, and psychosocial safety climate; factors that are increasingly linked to workers' health. This study aims to develop and establish the psychometric properties of one of the most comprehensive instruments measuring the psychosocial work environment to date: the Occupational Health and Well-being Questionnaire (OHWQ). STUDY DESIGN: A cross-sectional validation study is proposed to develop the OHWQ and document its psychometric properties. METHODS: The OHWQ was developed from validated instruments to which new items were added. The questionnaire includes psychosocial dimensions, along with indicators of psychological distress, musculoskeletal disorders, and well-being. It was administered to a sample of 2770 participants from a population working in the academic field. Exploratory and confirmatory factor analyses and the calculation of Cronbach's α coefficient were used to identify the variables, items, and, dimensions of the OHWQ and to document its main psychometric properties. RESULTS: The acceptability of the measurement model was evaluated by the reliability of the items, internal consistency between the items, and the convergent and discriminant validity. Construct validity was assessed using exploratory and confirmatory factor analyses. Using factor analyses and cut-off rules, the new instrument has 124 items grouped into 22 dimensions. The OHWQ demonstrated satisfactory reliability and validity, as well as reasonable fit indices. The internal consistency of the scales was also good (Cronbach's α = 0.68-0.96, median = 0.85). CONCLUSION: The OHWQ demonstrated good psychometric properties. It could be useful for both research purposes and for workplaces interested in developing concrete action plans aimed at improving the balance between psychosocial work stressors and resources.

Transverse pressure distributions in a simple model ear canal occluded by a hearing aid test fixture.

The sound field in a model ear canal with a hearing aid test fixture has been investigated experimentally and theoretically. Large transverse variations of sound pressure level, as much as 20 dB at 8 kHz, were found across the inner face of the hearing aid. Variations are greatest near the outlet port of the receiver and the vent port. Deeper into the canal, the transverse variations are less significant and, at depths greater than 4 mm, only a longitudinal variation remains. The model canal was cylindrical, 7.5 mm diameter, and terminated with a Zwislocki coupler to represent absorption by the human middle ear. The outer end of the canal was driven by the receiver in the hearing aid test fixture, with the acoustic output entering the canal through a 1 mm port. The hearing aid was provided with a 20-mm-long vent, either 1 or 2 mm in diameter. The sound field inside the canal was measured using a specially designed 0.2-mm-diam probe microphone [Daigle and Stinson, J. Acoust. Soc. Am. 116, 2618 (2004)]. In parallel, calculations of the interior sound field were performed using a boundary element technique and found to agree well with measurements.

Controlled experiments of the diffraction of sound by a curved surface.

Controlled measurements of the sound field from a point source above a curved surface are described. The measurements were made in the frequency range between 0.3 and 10 kHz, in the case of a rigid boundary and a surface of finite impedance. Receiver positions include all of the area within, and above, the shadow zone and for various source heights. Particular attention is given to the region across the shadow boundary. The measurements are compared to diffraction theory expressed in terms of a residue series, or creeping wave solution. The calculation is extended by removing restrictive approximations and by carrying the computation to higher-order terms. A numerical algorithm allows the extension to the general case of a finite impedance. Above the shadow boundary, the sound field is calculated using geometrical theory that accounts for reflections from a curved surface. Deep within the shadow, theory and measurements agree to, typically, 0.5 dB. The same agreement is obtained between measurements and the geometrical theory well above the shadow boundary. In the vicinity of the shadow boundary, both theories agree to within 0.5 dB but differ from the measured results by 2 to 5 dB. Finally, the theory is compared to measurements obtained outdoors above a grass covered curved ground with no refraction and above flat ground with refraction.

Automated quantification of bone and liver alkaline phosphatase isoenzymes of human serum.

Coupling two Technicon AAII samplers synchronised at 50 per hour with a 2 : 1 sample to wash ratio, sera are denatured and collected automatically. The incubation is done in continuous flow by passage through a U device made of large metallic needles soaked in a water bath at 60 +/- 0.1 degree C. This allows a very quick temperature equilibration and a very reproducible incubation time of 35 sec. Initial and residual activities of alkaline phosphatase (ALP: EC 3.1.3.1) are measured on a Rotochem II (Aminco) with the procedure recommended by the Société Française de Biologie Clinique (SFBC). For a mixture of bone and liver ALP, the initial rate constant of heat denaturation Kapp = (A X Kb) + (B X Kl), where A and B are the fractions of each isoenzyme in the mixture, and Kb and Kl the rate constants for bone (b) and liver (l) experimentally determined as 1.8 min-1 and 0.45 min-1 respectively. An equation was derived which converts the percent residual activity to a percentage of bone and liver isoenzyme: % bone ALP = 183--2.38 X % residual activity. This automated method was applied to 2700 people of both sexes from 4 to 100 years old.