Validation of an asthma questionnaire for use in healthcare workers

BACKGROUND

Previous studies have described increased occurrence of asthma among healthcare workers, but to our knowledge there are no validated survey questionnaires with which to study this occupational group.

AIMS

To develop, validate, and refine a new survey instrument on asthma for use in epidemiological studies of healthcare workers.

METHODS

An initial draft questionnaire, designed by a multidisciplinary team, used previously validated questions where possible; the occupational exposure section was developed by updating health services specific chemical lists through hospital walk-through surveys and review of material safety data sheets. A cross-sectional validation study was conducted in 118 non-smoking subjects, who also underwent bronchial challenge testing, an interview with an industrial hygienist, and measurement of specific IgE antibodies to common aeroallergens.

RESULTS

The final version consisted of 43 main questions in four sections. Time to completion of the questionnaire ranged from 13 to 25 minutes. Test-retest reliability of asthma and allergy items ranged from 75% to 94%, and internal consistency for these items was excellent (Cronbach's alpha > or = 0.86). Against methacholine challenge, an eight item combination of asthma related symptoms had a sensitivity of 71% and specificity of 70%; against a physician diagnosis of asthma, this same combination showed a sensitivity of 79% and specificity of 98%. Agreement between self-reported exposures and industrial hygienist review was similar to previous studies and only moderate, indicating the need to incorporate more reliable methods of exposure assessment. Against the aerollergen panel, the best combinations of sensitivity and specificity were obtained for a history of allergies to dust, dust mite, and animals.

CONCLUSIONS

Initial evaluation of this new questionnaire indicates good validity and reliability, and further field testing and cross-validation in a larger healthcare worker population is in progress. The need for development of more reliable occupational exposure assessment methods that go beyond self-report is underscored.

Incidence and prevalence of dementia in a multiethnic cohort of municipal retirees

BACKGROUND

Multiethnic population-based studies of dementia are lacking in the literature; therefore, we conducted a study to determine the incidence and prevalence of dementia among, black, white, and Hispanic municipal retirees age 50 and older.

METHODS

In 1991, city of Houston municipal workers who retired between 1980 and 1984 received in-home screening for cognitive impairment using the Mini-Mental State Examination and were referred for comprehensive neurologic evaluation if indicated. Families of deceased retirees were interviewed, medical records were reviewed, and death certificates were obtained to determine case status of the retiree. Study participation was 90%.

RESULTS

Crude prevalence of dementia, among retirees age 60 and older, was 2.65 per 100 population. Age-adjusted to the 1970 US population, age 60 to 80, the prevalence was 1.85 per 100 population. Age-adjusted prevalence of dementia was similar among Hispanic and black men, 4.75 and 4.80 respectively, and lowest among white men, 2.42 per 100 population. Forty-three percent of the prevalent cases (30% of the incidence cases) were not previously diagnosed. The cumulative incidence of dementia calculated to age 80 was 39% for Hispanic men, 28% for black men, and 14% for white men. Fifty-five percent of the incidence cases were diagnosed as having ischemic vascular dementia (IVD), 20% as having probable or possible Alzheimer's dementia (AD), and 25% as having unspecified dementia.

CONCLUSIONS

Risk of dementia by age 80 was more pronounced for Hispanic and black men compared with white men. IVD was the predominant cause of dementia among both black and white men. Grouping Hispanics with whites may mask differences when studying dementia.