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Validation of a light questionnaire with real-life photopic illuminance measurements: the Harvard Light Exposure Assessment questionnaire.

ABSTRACT: Shift work, which necessitates light exposure at night, is now considered a probable carcinogen. To study the effects of light on chronic diseases like cancer, methods to measure light exposure in large observational studies are needed. We aimed to investigate the validity of self-reported current light exposure.We developed a self-administered semiquantitative light questionnaire, the Harvard Light Exposure Assessment (H-LEA) questionnaire, and compared photopic scores derived from this questionnaire with actual photopic and circadian measures obtained from a real-life 7-day light meter application among 132 women (85 rotating night shift workers and 47 day workers) participating in the Nurses' Health Study II.After adjustment for age, body mass index (BMI), collection day, and night work status, the overall partial Spearman correlation between self-report of light exposure and actual photopic light measurements was 0.72 (P < 0.001; Kendall ? = 0.57) and 0.73 (P < 0.0001; Kendall ? = 0.58) when correlating circadian light measurements. There were only minimal differences in accuracy of self-report of light exposure and photopic or "circadian" light measurement between day (r = 0.77 and 0.78, respectively) and rotating night shift workers (r = 0.68 and 0.69, respectively).The results of this study provide evidence of the criterion validity of self-reported light exposure using the H-LEA questionnaire.This questionnaire is a practical method of assessing light exposure in large-scale epidemiologic studies.

SUBMITTER: Bajaj A

PROVIDER: S-EPMC3340010 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature

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Validation of a light questionnaire with real-life photopic illuminance measurements: the Harvard Light Exposure Assessment questionnaire.

Bajaj Archna A Rosner Bernard B Lockley Steven W SW Schernhammer Eva S ES

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology 20110701 7

<h4>Background</h4>Shift work, which necessitates light exposure at night, is now considered a probable carcinogen. To study the effects of light on chronic diseases like cancer, methods to measure light exposure in large observational studies are needed. We aimed to investigate the validity of self-reported current light exposure.<h4>Methods</h4>We developed a self-administered semiquantitative light questionnaire, the Harvard Light Exposure Assessment (H-LEA) questionnaire, and compared photop ...[more]

PMID: 21737411

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Project description:BackgroundFalls are the number one cause of injuries in older adults, and are particularly common in long-term care (LTC). Lack of objective evidence on the mechanisms of falls in this setting is a major barrier to prevention. Video capture of real-life falls can help to address this barrier, if valid tools are available for data analysis. To address this need, we developed a 24-item fall video analysis questionnaire (FVAQ) to probe key biomechanical, behavioural, situational, and environmental aspects of the initiation, descent, and impact stages of falls. We then tested the reliability of this tool using video footage of falls collected in LTC.MethodsOver three years, we video-captured 221 falls experienced by 130 individuals in common areas (e.g., dining rooms, hallways, and lounges) of two LTC facilities. The FVAQ was developed through literature review and an iterative process to ensure our responses captured the most common behaviours observed in preliminary review of fall videos. Inter-rater reliability was assessed by comparing responses from two teams, each having three members, who reviewed 15 randomly-selected videos. Intra-rater reliability was measured by comparing responses from one team at baseline and 12 months later.ResultsIn 17 of the 24 questions, the percentage of inter- and intra-rater agreement was over 80% and the Cohen's Kappa was greater than 0.60, reflecting good reliability. These included questions on the cause of imbalance, activity at the time of the fall, fall direction, stepping responses, and impact to specific body sites. Poorer agreement was observed for footwear, contribution of clutter, reach-to-grasp responses, and perceived site of injury risk.ConclusionsOur results provide strong evidence of the reliability of the FVAQ for classifying biomechanical, behavioural, situational, and environmental aspects of falls captured on video in common areas in LTC. Application of this tool should reveal new and important strategies for the prevention and treatment of falls and fall-related injuries in this setting.

Project description:To compare measurements of the full-field photopic negative response (PhNR), as well as intra-subject variation in the PhNR, using time and time-frequency domain analyses.Full-field ERGs were recorded from 20 normally sighted subjects (aged 24-65 years) elicited by a long-wavelength pulse (3 cd s m-2) presented against a short-wavelength adapting field (12.5 cd m-2). Three to 10 waveforms were obtained from each subject, and each waveform was analyzed using standard time domain analyses of the PhNR, as well as a discrete wavelet transform (DWT) to extract time-frequency components that correspond to the PhNR. Three different measures of the PhNR were derived and compared: (1) amplitude at the PhNR trough; (2) amplitude at 72 ms following stimulus onset; (3) energy in the 11 Hz, 60-120 ms DWT frequency bin that corresponds to the PhNR. In addition, the effect of normalizing the PhNR by the b-wave was evaluated for each of the measures. Coefficients of variation (CVs) were computed for each definition to evaluate intra-subject variation.PhNR amplitudes measured at the trough and at 72 ms were significantly correlated (r = 0.88, p < 0.001). Additionally, PhNR energy derived by DWT was significantly correlated with the amplitude measured at the trough (r = 0.64, p = 0.002) and at 72 ms (r = 0.60, p = 0.005). Mean (±SD) intra-subject CVs were 26 % (15 %), 49 % (26 %), and 30 % (15 %), for measures at the trough, 72 ms, and DWT, respectively. Normalization by the b-wave amplitude (i.e., PhNR/b) had minimal effect on the intra-subject CVs, whereas normalization by the sum of the b-wave and PhNR amplitudes (i.e., PhNR/[b + PhNR]) substantially reduced the CVs for all three measures (mean CVs were less than 17 % for all conditions).Although each PhNR definition has advantages and disadvantages, all three metrics provide similar estimates of the PhNR. Intra-subject CVs, however, were relatively high for measurements made at 72 ms, indicating that definitions based on a fixed time point may introduce variability. The substantial decrease in intra-subject variation after normalization by the sum of the PhNR and b-wave amplitudes may be advantageous under some conditions.

Project description:The seven-item QEAS-7 questionnaire (exposure to asbestos questionnaire) has been designed as a useful and simple tool to establish the probability of exposure to asbestos. The objective of the present study is to validate the QEAS-7 following the recommended methodology. The QEAS-7 was prospectively administered to 90 subjects with and without asbestos-related disease (ARD), on two consecutive occasions by two independent researchers. Logical and content validity was evaluated by a committee of experts and construct validity through hypothesis testing. Intra- and interobserver reliability was assessed by calculating Cohen's Kappa index (κ), which was estimated as weak if below 0.40, moderate if between 0.41 and 0.60 and good/very good if above 0.60. The comparison between proportions was examined using Pearson's Chi-square test. The majority of participants (88.9%) were male. Mean age was 70.8 years (SD = 8.4) and most of the sample had completed primary education but had not progressed further (62.2%). Forty-three had ARD. The logical, content and construct validity of the QEAS-7 was considered adequate both by a committee of experts and by the users interviewed. The mean administration time was 9 min and 25 s (SD = 3 min and 49 s). The verification of the five hypotheses confirmed the construct validity and the intra- and interobserver reliability to be κ = 0.93 and κ = 0.50 respectively. The concordance in the estimation of asbestos exposure was κ = 0.65. The QEAS-7 is a simple, valid and reliable tool for estimating the probability of exposure to asbestos. Its application in clinical practice appears justified. What is already known about this subject? No studies have been published to date on the validation of specific questionnaires designed to determine asbestos exposure for routine use by healthcare staff in the clinical setting. What are the new findings? This questionnaire can be considered a comprehensible, viable, valid and reliable instrument for identifying exposure to asbestos. Its brevity and simplicity of administration make it ideally suited for use in daily clinical practice. How might this impact on policy or clinical practice in the foreseeable future? This questionnaire can be of help for physicians attending to patients with suspected asbestos-related diseases both in the hospital and in the primary care setting.

Project description:BACKGROUND:Measuring the health-related quality of life (HRQoL) of adolescents, including those with cerebral palsy (CP) (the major cause of childhood physical disability worldwide) in Bangladesh is pertinent although there is a dearth of validated instruments for assessing this concept. For application in a case-control study comparing HRQoL between adolescents with CP and peers without disability in Bangladesh (a typical low- and middle-income country) we cross-culturally translated and psychometrically tested KIDSCREEN-27. METHODS:KIDSCREEN-27 was translated to Bengali using forward and backwards translation protocol and interviewer administered to adolescents with CP and their age and sex matched peers without disability. Primary caregivers were included for proxy-report. Sociodeomgraphic characterists and clinical information were extracted from the Bangladesh Cerebral Palsy Register (BCPR) and adolescent mental health was assessed using the Bengali version Strenghts and Difficulties Questionnaire (SDQ). Feasibility, floor and ceiling effect, internal consistency, content and construct validity of KIDSCREEN-27 were tested. RESULTS:Feasibility, floor and ceiling effect and internal consistency of KIDSCREEN-27 was good for both self- and proxy-report questionnaires; nil missing scores except 'school environment' (11.0% to 74.7%) which correlated to rates of non-school attendance; floor and ceiling effect ?10.4% except 'peers and social support' 23.4%; Cronbach's alpha 0.67 to 0.91. Instrument validity was strong; factor analysis reflected original instrument dimensions within one to three factors and difference in known groups was observed by CP and adolescent mental health (p?<?0.05). CONCLUSION:KIDSCREEN-27 successfully translated to Bengali and both the self and proxy-report questionnaires showed good psychometric properties indicating suitability for case-control assessment of HRQoL between adolescents with CP and peers without disability in Bangladesh.

Dataset Information

Validation of a light questionnaire with real-life photopic illuminance measurements: the Harvard Light Exposure Assessment questionnaire.

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Validation of a light questionnaire with real-life photopic illuminance measurements: the Harvard Light Exposure Assessment questionnaire.

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