Divide Data sources either by:
| 1. Population Data 
 
 | 
| 2. Health Events 
 
 | 
| 3. Population Based Surveys 
 
 | 
OR by :
|  1.  Mortality | 
| 2. Morbidity 
 | 
|  3.  Surveys - done regularly such as the National Health Survey or one-off 
 | 
|  4.  Research - literature via medline | 
|  5.  Non-NHS sources such as fire, police other registers | 
A bit about each of these sources with their advantages and disadvantages would be helpful to know. Most of the detail of this is in Donaldson & Donaldson.
