Dr. Smith provided an overview of the use of vignettes to standardize measurement of work disability. In motivating the usefulness of vignettes, he explained that disability insurance enrollment and work disability is much higher in the Netherlands than in the United Sates, but reports of chronic diseases are higher in the latter. In England, there are lower rates of diseases (based both on self-reports and administrative data), but Americans rate health better on a five-point general health status measure. The distributions of self-reported health may vary because the thresholds corresponding to poor, fair, good, very good, and excellent might differ across the two countries (see Figure 1). Vignettes have been used to understand differences in thresholds across populations and to correct for these differences.
Vignettes are a brief description of a hypothetical person. Each respondent is asked to self-report whether they have a health problem that limits the amount or type of work they can do, on a five-point scale from not at all to extremely limited. They are then asked to rate individuals appearing in brief vignettes on the same scale. For example, a vignette for an individual with emotional problems follows:
[Tamara] has mood swings on the job. When she gets depressed, everything she does at work is an effort for her and she no longer enjoys her usual activities at work. These mood swings are unpredictable and occur two or three times during a month.
|FIGURE 1. Comparing Self-Reported Health Across Two Counties|
The vignettes vary in terms of severity and condition. Administration of the full set of vignettes takes approximately eight minutes. The information from the vignettes is then used to standardize rankings across groups so that comparisons are no longer biased.
Dr. Smith has been involved in efforts to add work disability vignettes to the CentERpanel in the Netherlands and the HRS, PSID and the RAND Internet Panel in the United States. The internet panels provide the advantage of experiments in question wording and quick turnaround time.
Key findings from analyses by Dr. Smith and colleagues suggest that United States respondents have a stricter standard in identifying work disability than Dutch respondents. For example, 11.1% of Americans classified Tamara (above) as being extremely or severely limited whereas 17.6% of Dutch did so. Threshold differences were also found within countries by gender, education and health. For example, women and less educated respondents in the United States had stricter standards than men, those with emotional problems and those in pain were more likely to classify an illustrative case as having a limitation.
Evidence from experimental modules has provided some evidence on how best to administer the vignettes. For example, female respondents seemed to have strict standards for classifying emotional problems as causing work limitations; however, female respondents were given only female names in the vignettes whereas male respondents were given male names. Further experiments showed that it is the gender of the vignette that matters and not the gender of the respondent.
In conclusion, vignettes can help to make reported work disability (or other measures of disability) comparable across populations. Large differences in reported work disability cannot be explained by differences in health between the two countries. Future work will extend these tools to additional countries, cross-walk them with objective measures like grip strength, and extend them to other measures of disability such as ADLs and IADLs.