Objective: To describe the status and characteristics of under-reporting of death cases within national disease surveillance system (DSPs).
Methods: Six villages (communities) were selected in each of the 161 counties of DSPs by multi-stage random cluster sampling methods, the information of resident from 2006 to 2008 was collected, and a survey of the under-reporting deaths cases was carried out which covered 6 422 667 people in all. The under-reporting rate was estimated by ages, genders and regions. The mortality was compared before and after the adjustment of the under-reporting rate.
Results: The total crude rate of under-reporting of whole nation was 16.68% (6271/37 603), and after the adjustment by weight the rate was 17.44%; the under-reporting rate of urban areas was a bit lower than rural areas, which were 16.08% and 18.14% respectively (P < 0.01); the under-reporting rate of middle and west regions were higher than the east, which were 19.27%, 18.15% and 15.46% respectively (P < 0.01). The under-reporting rate of children of under-five years old was much higher than that of people of five and above-five years old, which were 34.95% and 16.90% respectively (P < 0.01). The gender difference was especially obvious in age group 0-4, for women 39.36% while 31.93% for men. After adjusted by under-reporting rate, the mortality rate of male raised from 6.38‰ to 7.74‰ and for female raised from 4.66‰ to 5.64‰. In the middle region, the mortality rate of male raised from 6.49‰ to 8.00‰ and for female raised from 4.59‰ to 5.73‰ after the adjustment. And the mortality rate of male in age group 0-4 raised from 2.48‰ to 3.64‰ and for female raised from 1.98‰ to 3.27‰. Of which in urban area, the mortality rate of male was much higher than female before the adjustment, which were 1.76‰ and 1.39‰ respectively; however, the mortality rate of male was a bit lower than female after the adjustment, which were 2.26‰ and 2.41‰ respectively. The mortality in male of five and above-five raised from 6.60‰ to 7.69‰ after the adjustment while in female raised from 4.80‰ to 5.77‰.
Conclusion: There are regional and age-group differences of the under-reporting rate of the National Disease Surveillance System. The gender differences mainly shows in age 0-4.