Impacts of using different standard populations in calculating age-standardised death rates when age-specific death rates in the populations being compared do not have a consistent relationship: a cross-sectional population-based observational study on US state HIV death rates.

Objective: To examine if the rankings of state HIV age-standardised death rates (SDRs) would be different if different standard populations (SPs) were used when age-specific death rates (ASDRs) in states being compared do not have a consistent relationship.

Design: A cross-sectional population-based observational study.

Setting: 36 states in the USA.