Why might a central registry have a high death certificate only rate?

A central registry may have a high death certificate only rate primarily due to an incomplete reporting list. This situation arises when the registry does not have a comprehensive or updated list of reportable cases, leading to the identification of deaths solely through death certificates. In such cases, the registry may be missing cases that could have been captured through other reporting mechanisms, such as hospitals, physician offices, or cancer treatment centers. Thus, when a central registry cannot adequately document all events and patients in its area, the cases that are recorded may predominantly come from death certificates, hence resulting in a higher death certificate only rate.

Other factors, such as efficiently processing death certificates or receiving them from other states, could contribute to the number of death certificates processed but do not directly correlate to the overall completeness of case reporting. Similarly, capturing all reported cases would lower the death certificate only rate since it would imply all cases are being recorded through appropriate channels, rather than exclusively from death certificates.