I don't know my child's asthma risk: evidence against satisficing as an explanation for 'don't know' responses

Several studies suggest that "don't know" (DK) responses to risk perception items may represent meaningful expressions of uncertainty about disease risk. However, researchers are often discouraged from including a DK response option in survey items due to concerns about respondents overusing it to minimize cognitive effort-a phenomenon often referred to as satisficing. Our objective was to investigate whether patterns of DK responses to risk perception survey items were consistent with satisficing behavior. We conducted a secondary analysis of survey data from 814 parents and guardians (hereafter caregivers) of children with asthma. Caregivers answered 18 items assessing their perceived risk of their child experiencing two types of poor asthma outcomes: asthma exacerbation, and low asthma control. We examined differences in the frequency and distribution of DK responses across all 18 items and by type of risk perception item (i.e., 2 vs. 5 response options, absolute vs. comparative risk). We found that 32% (n=548) of respondents marked DK at least once. Of the 266 caregivers who provided any DK response, most did so for only 1 or 2 items (51.9%, n=138), and only 6% (n=15) answered DK to more than half of the items. Using random coefficient Poisson models, we found more DK responding for dichotomous absolute (30.1%) than ordinal absolute items (5.3%), b=1.72, p<.001. We also found fewer DK responses to the ordinal absolute items than the comparative items (8.2%), b=-0.49, p<.001. Using Chi-square tests, we found that inattentive responding was not associated with responding DK. Our findings suggest that satisficing is unlikely to completely explain DK responding to perceived risk survey items. Researchers who exclude DK response options from risk perception survey items may obtain an incomplete understanding of their study sample's beliefs about risk.