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Biomedical subjects

K B Christensen

Publications and source records attributed to K B Christensen.

3 recordsLinked to original sources
PubMed2006

Eye blink frequency during different computer tasks quantified by electrooculography.

The purpose of the study was to evaluate electrooculography (EOG) as an automatic method to measure the human eye blink frequency (BF) during passive and interactive computer tasks performed at two screen heights. Ten healthy subjects (5 males and 5 females) participated in the study in a 23 degrees C temperature and 30-35% relative humidity controlled simulated office environment. Each test subject completed a 2 x 10 min active task of computer work and a 3 x 10 min passive task of watching a film on a video display unit (VDU). Both tasks included two viewing angles: standard (the monitors' upper edge was in the same height as the subjects' eyes) and low (lowered by 25 degrees). EOG signals were recorded with two Ag/AgCl surface electrodes positioned above and below the right eye, and a reference electrode was placed behind the ear. The experiments were video filmed, and eye blinks were counted manually from the video recordings and compared to the EOG measurements. The method showed a high validity to detect blinks during computer work: 95.4% of the blinks were retrieved by the EOG method and very few artefacts from eye movements were erroneously classified as eye blinks (2.4%). By use of the EOG method, the computer task was found to significantly decrease the BF by 69% compared to the passive task (P < 0.001), and a small decrease (12-14%) was found by lowering the viewing angle by 25 degrees.

Adult↗
PubMed2006

Burnout as a predictor of self-reported sickness absence among human service workers: prospective findings from three year follow up of the PUMA study.

AIM: To investigate whether burnout predicts sickness absence days and sickness absence spells in human service workers. METHOD: A total of 824 participants from an ongoing prospective study in different human service sector organisations were eligible for the three year follow up analysis. Burnout was measured with the work related burnout scale of the Copenhagen Burnout Inventory. Sickness absence was measured with self-reported number of days and spells during the last 12 months before the baseline and the follow up survey. A Poisson regression model with a scale parameter was used to account for over dispersion. A linear regression model was used for analysing changes in burnout and absence between baseline and follow up. RESULTS: Burnout was prospectively associated with both sickness absence days and sickness absence spells per year. Differences in sickness absence days varied from a mean of 5.4 days per year in the lowest quartile of the work related burnout scale to a mean of 13.6 in the highest quartile. An increase of one standard deviation on the work related burnout scale predicted an increase of 21% in sickness absence days per year (rate ratio 1.21, 95% CI 1.11 to 1.32) after adjusting for gender, age, organisation, socioeconomic status, lifestyle factors, family status, having children under 7 years of age, and prevalence of diseases. Regarding sickness absence spells, an increase of one standard deviation on the work related burnout scale predicted an increase of 9% per year (rate ratio 1.09, 95% CI 1.02 to 1.17). Changes in burnout level from baseline to follow up were positively associated with changes in sickness absence days (estimate 1.94 days/year, SE 0.63) and sickness absence spell (estimate 0.34 spells/year, SE 0.08). CONCLUSION: The findings indicate that burnout predicts sickness absence. Reducing burnout is likely to reduce sickness absence.

Adult↗