A comparison of stereopsis with ANVIS and F4949 night vision goggles.

BACKGROUND: This study was undertaken to see if the model of NVG affects stereoacuity. METHODS: We tested 13 male and 2 female aircrew with the Aviator's Night Vision Imaging System (ANVIS) and F4949 NVGs. Visual acuity was measured using the NVG Resolution Grid and stereopsis was determined using a modified Howard-Dolman test. RESULTS: In simulated light conditions, average stereoscopic threshold using the F4949 NVG (17.35 arc s) was not significantly better than the ANVIS NVG (18.42 arc s), the mean difference being 1.07 arc s (95% confidence limits, -2.85 to 4.99). CONCLUSIONS: The Howard-Dolman test proved to be effective in eliminating monocular clues, thus validating its use in testing NVG stereopsis. The distribution of visual acuities across subjects and goggle models was too narrow to evaluate the effect of visual acuity on stereoacuity in NVGs. Differences in trial means during the course of the study indicated the presence of a "learning" effect on the Howard-Dolman test.

An evaluation of Duke University's LIVE FOR LIFE health promotion program on changes in worker absenteeism.

The effect of an employer-sponsored health promotion program on worker absenteeism is examined over a 4-year period in a group of 4972 Duke University hourly employees. Program participants experienced an average of 4.6 fewer absentee hours in the third year of program availability than did nonparticipants, after controlling for baseline absenteeism, gender, race, education, and age. These results suggest that employer-sponsored health promotion initiatives can have a favorable influence on absenteeism.

The impact of legislation on self-reported safety belt use in a working population.

To assess the impact of safety belt laws, we compared self-reported use of safety belts among employed residents of states with primary, secondary, and no laws in a group of 17,830 volunteer health profile participants. Failure to wear safety belts at least 80% of the time was reported by 22% of subjects covered by primary laws, 23% of those covered by secondary laws, and 39% of those not covered by any law.

Utilization of preventive health services by an employed population.

To determine the utilization rates of selected preventive services in an employed population, we analyzed the responses of 18,053 health profile participants. Overall utilization rates for preventive services were high: 86.0% of respondents had their blood pressure checked, 94.0% of all women had a Pap smear and 81.3% had clinical breast examinations, 42.4% of respondents aged 40 and older had a rectal examination and 31.8% of those aged 50 and older had a test for occult blood in the stool, and 33.7% had a routine sigmoidoscopy. With the exception of blood pressure screening, the percentage of our respondents utilizing preventive services was considerably higher than the corresponding percentages in the US population as reported in the National Health Interview Survey. Nevertheless, the results suggest substantial opportunity for employers to encourage the appropriate use of preventive health services among employees.

Correlates of motor-vehicle safety behaviors in working populations.

To determine the prevalence and correlates in a working population of failure to wear seat belts, drinking and driving, and speeding, we examined the responses of 18,046 health-profile participants. Twenty-four percent of subjects reported failure to wear seat belts at least 80% of the time. Twenty-two percent reported speeding at least 10 miles per hour over the speed limit when traffic permits. Twenty-three percent reported traveling at least once a month with a driver who had two or more drinks. Correlates of high-risk behaviors included male gender and youth. Educational attainment was inversely associated with seat-belt nonuse but directly related to speeding and drinking/driving. Our findings suggest a substantial opportunity to help employees lower important risks for serious motor-vehicle injury.

Prevalence and characteristics of employees reporting heavy or problem drinking.

INTRODUCTION: This study examined the prevalence and demographic characteristics of chronic heavy drinkers, binge drinkers, those who report a problem with alcohol, and those at high risk for alcohol-related problems. METHODS: The sample comprised a worksite population of 18,053 employees. The study was based on responses to questions contained in a confidential health profile administered to employees at seven companies by an outside vendor (Johnson & Johnson Health Management, Inc.). RESULTS: Almost 1 in 4 participants (23.0%) was found to be at risk for alcohol-related problems. About 1 in 5 respondents (20.1%) reported binging, 1 in 10 reported chronic heavy drinking (9.8%), and 2.6% reported a drinking problem within the past month. Younger respondents were more likely to report binging but older respondents were more likely to report chronic heavy drinking. Men were more than twice as likely to report binging and almost four times as likely to report chronic heavy drinking, but only one and one-half times as likely to report a drinking problem within the past month. Other differential demographic associations with alternative measures of heavy drinking are described. CONCLUSION: The results suggest that a health profile administered at the worksite can be an effective screening tool for identifying employees at high risk for alcohol-related problems.

Magnitude estimation of loudness. II: Loudness perception in presbycusic listeners.

Because clinical methods most commonly used for assessing loudness are indirect measures that require one normal or near normal ear, loudness perception has not been studied thoroughly in listeners with symmetrical hearing loss. In this investigation, loudness perception was studied in three groups of listeners: normal listeners, listeners with asymmetrical sensorineural hearing loss, and individuals with bilaterally symmetrical hearing impairment due to presbycusis. In Experiment 1, a Magnitude Estimation of Loudness (ME) technique was compared to Alternate Binaural Loudness Balance ( ABLB ) results for subjects with asymmetrical hearing impairment. Results indicate that ME and ABLB measurements produce similar evidence of abnormally rapid growth of loudness in asymmetrically impaired listeners. In Experiment 2, loudness growth in individuals with normal hearing or with presbycusic hearing impairment was determined from ME measurements. Although presbycusic subjects tended to have steeper loudness functions than normal subjects, the differences did not reach statistical significance except at 6000 Hz, suggesting that, as a group, presbycusic listeners display little, if any, recruitment of loudness.