When and why people are comparatively optimistic about future health risks: The role of direct and indirect comparison measures

Abstract

The goal of the current research was to test whether direct versus indirect measures of comparative optimism yield different results as a function of health risk severity and prevalence. A random-digit sample of community residents (N = 259) responded to interview questions about perceived vulnerability using both direct (i.e. self-to-peer risk) and indirect comparison measures (i.e. separate questions about self and peer risk). Responses to direct comparison measures were more affected by prevalence, whereas indirect comparison measures were more affected by severity. These results may offer guidance to researchers and practitioners about when it may be more appropriate to use direct versus indirect measures of comparative health risk.

Keywords:

• unrealistic optimism
• optimistic bias
• absolute and comparative risk
• indirect and direct method
• severity and prevalence

Notes

1. Our sample had more female participants than male participants, which is consistent with data on selection biases and nonresponders in behavioral research (Lyness & Kropf, 2007; Phares & Compas, 1992; Woollett, White, & Lyon, 1982). Gender, however, was generally not associated with comparative optimism (only 1 significant effect out of the 16 risks: Female participants felt less optimistic about experiencing arthritis, r = 0.23, p < 0.05). Moreover, when gender was included in the main analyses, it did not tend to interact with any of the main variables of interest (e.g. severity, prevalence).

2. An anonymous reviewer noted that some participants may have been currently experiencing a health outcome (e.g. cancer), which may affect the vulnerability ratings. We note that this concern only applies to a subset of the risks and is not often discussed in prior studies of comparative optimism. Furthermore, our participants could skip questions or say “I don't know” if they were unsure how to answer, which might have been options for participants who currently incurred the health risk.

3. A pilot study was conducted with college students who were randomly assigned to make absolute self, absolute peer, and comparative risk estimates in one of the four orders. The overall incidence of comparative optimism vs. pessimism at the level of specific health risks did not systematically differ across the four order conditions (χ²s < 5.2, ps > 0.40). The magnitude of bias varied somewhat across conditions, but direct and indirect comparative optimism was found in all order conditions (all ts > 2.2, ps < 0.05). Finally, the correlations between prevalence/severity and comparative optimism did not differ (all Fs < 2, ps > 0.10).