Associations Between Personal Protective Measures and Self-Reported Tick-Borne Disease Diagnosis in Indiana Residents

Several personal protective measures (PPMs) are recommended to prevent tick-borne diseases (TBD). We aimed to quantify the strength of seven PPMs and self-reported TBD diagnosis associations and to understand what variables modify these associations. In June-July 2018, with a cross-sectional study design, we surveyed a sample of adult Indiana state residents. Overall, 2927 participants were eligible for this analysis. All data were self-reported. We used the double robust approach of stabilized inverse probability weighting and propensity score adjustment to obtain ORs. Approximately 5% of participants (n = 142) self-reported TBD diagnosis. Practicing different PPMs ranged from 48% for treating outdoor clothing with special bug-spray to 83% for walking on established trails. Using insect repellent on exposed skin was protective against TBD diagnosis [OR (95% CI): 0.55 (0.35, 0.88)]. A thorough body/clothes check after being outdoors was also protective against TBD diagnosis [OR (95% CI): 0.40 (0.25, 0.67)]. In stratified analyses, TBD knowledge, safety worry because of ticks, avoiding outdoors because of ticks, and pet TBD risk modified the associations between different PPMs and self-reported TBD diagnosis. In the state of Indiana, thorough body/clothes check after being outdoors and use of insect repellent on exposed skin might be strongly effective in preventing TBD. The protective effect of different PPMs might be stronger among people with high TBD knowledge, high safety worry because of ticks, high avoidance of being outdoors because of ticks, and low pet TBD risk. These results might be useful in the design of intervention programs.