S1 Appendix -

<div><p>This study used the nationally representative prospective study of the Household, Income and Labour Dynamics in Australia (HILDA) survey cohort to examine the association of pet ownership (dog, cat, bird, fish, and others) with the risk of all-cause mortality using propensity score matching based on a wide range of factors. The study sample included 15,735 participants who completed the questionnaire on pet ownership in 2018. The HILDA survey sample was matched to the National Death Index through 2022 to assess death during the follow-up period. Statistical analysis was weighted by the inverse of the propensity score in the generalized estimating equation. During the 4-year follow-up period, 377 of 15,735 (2.4%) participants died. The odds ratios (ORs) for all-cause mortality were 0.77 (95%CI: 0.59–0.99) for dog owners compared to non-pet owners after controlling for related socio-demographic, physical, psychological, and social factors. The Sobel test showed a partial mediating effect of physical activity level on the relationship between dog ownership and all-cause mortality. Ownership of cats, birds, fish, and others showed no clear association with mortality, despite owners having similar socio-demographics characteristics to dog owners. Companionship and exercise of a pet dog may be recommended as a component of health promotion policy, and may have an important role to play in promoting health aging.</p></div>