Background: Poor sleep disproportionately affects disadvantaged populations, but the role of housing tenure as a structural determinant is underexplored. Renters may experience worse sleep for reasons relating to material and psychosocial factors. Income likely modifies this relationship, because higher-income renters have more resources to mitigate housing problems and select into homes and neighbourhoods that support sleep health. We examined whether housing tenure (renter/owner-occupier) is associated with sleep quality, whether this relationship varies by income, and whether tenure-related inequalities in sleep outcomes have changed over time.

Methods: We analysed 35,880 observations over three waves of data (2013, 2017, 2021) from 15–84-year-olds in the Household, Income & Labour Dynamics in Australia survey. Sleep quality was self-reported on a 4-point scale. Using ordinal logistic regression, we examined tenure-sleep associations and income-tenure interactions and estimated predicted probabilities of poor sleep quality ("fairly” or “very” bad). Effect measure modification by household income was assessed on the additive scale with income benchmarked to the national distribution (lower 40% vs upper 60%). Models were adjusted for sociodemographic, employment, health and household composition variables, and accounted for household clustering.

Results: Tenure was associated with sleep in all years. Renters consistently had ~4 percentage points higher probability of poor sleep quality (proportional OR in 2013=1.23 (95% CI:1.11,1.33); 2017 OR=1.25 (1.15,1.36); 2021 OR=1.18 (1.08,1.28)). In 2017 and 2021, there was clear evidence of effect modification by income: among lower-income households in 2017, renters had 7.4 percentage points higher probability of poor sleep than owner-occupiers (33.0% vs 25.6%), while the tenure gap was only 2.3 percentage points for higher-income households (difference on additive scale=5.1 (95% CI:1.9,8.3)). The 2013 income difference in tenure gap was smaller and non-significant (2.6 percentage points, 95% CI:-0.6,5.8).

Conclusion: Persistent tenure-related inequalities suggest systemic housing factors undermine sleep health for renters, particularly among economically disadvantaged households.