Ranking regional drowning mortality rates: population-based versus aquatic area-based rate

Area of Science:

• Public Health
• Epidemiology
• Environmental Health

Background:

• Population-based rates are commonly used for drowning mortality, but may not accurately reflect localized risk exposure.
• Taitung County, Taiwan, presents a unique case study due to its extensive coastline and aquatic environments.

Purpose of the Study:

• To compare drowning mortality rate rankings in Taitung County using population-based versus aquatic area-based denominators.
• To determine if aquatic area is a more suitable metric for assessing drowning risk exposure.

Main Methods:

• Calculated drowning mortality rates per 100,000 persons (population-based).
• Calculated drowning mortality rates per 100,000 km² of aquatic area.
• Compared the resulting township rankings between the two calculation methods.

Main Results:

• Highest population-based rates were in Changbin, Lanyu, Donghe, and Chenggong.
• Highest aquatic area-based rates were in Lanyu, Lyudao, Chenggong, and Taitung City.
• Taitung City's rank significantly increased from 10th (population-based) to 4th (aquatic area-based).

Conclusions:

• Drowning mortality rate rankings differ substantially when using aquatic area as the denominator compared to population.
• Aquatic area-based rates offer a more precise assessment of drowning risk exposure in regions with significant aquatic environments.