Our methodology for estimating the population for each disease in China involves a multi-pronged approach. We employ both our traditional research and analysis techniques as well as methods geared specifically towards understanding the unique features of disease epidemiology in the Chinese market. For each disease we:
- Translate Chinese literature sources for epidemiology studies
- Model the current disease population based on the percentage of the population living in urban areas versus those living in rural areas
- Forecast future disease trends based on the projected urbanization rate for China and the projected changes in disease incidence or prevalence based on lifestyle changes
The process begins with a thorough data collection and evaluation phase:
- Full search of standard medical search engines
- Full search of Chinese literature database
- Full search of worldwide health organizations
- Full search of region- or country-specific sources such as national health organizations and governments
We place particular emphasis on identifying, evaluating and translating the most recently published Chinese studies and rely on those that include the correct disease definition and that present China-specific population- or community-based, age- and gender-specific data collected on a large-scale regional or national level. We identify all sources and comment on regional variation within China.
Using one or more of these Chinese studies, we then:
- Identify the appropriate age- and gender-specific incidence and/or prevalence rates for each disease
- Identify overall incidence and/or prevalence rates for urban and rural populations
- Calculate base-year patient population estimates by multiplying the above rates by United Nations population figures
- Project future changes in age- and gender-specific rates based on expected changes in lifestyle and/or historical trends in incidence or prevalence
- Forecast the 10-year patient population (e.g. 2005, 2010 and 2015) utilizing projected changes in the incidence and/or prevalence rate, projected changes in the urban/rural mix of the population and United Nations projected population figures for the Chinese population
We detail a number of discrete subpopulations, including age and gender, and urban versus rural. As appropriate, we also identify other subpopulations such as disease severity, subtype or comorbidity subpopulations.
Our estimates are informed by primary research in three respects. Through interviews with academic and medical thought-leaders in China, we confirm that we have identified all relevant studies and we seek to validate our estimates against expert opinions. In addition, if the literature lacks high-quality data on which to base our total prevalence estimates or subpopulation schemes, we depend upon expert opinions in generating these estimates.