00498nas a2200169   4500000000100000000000100001008004100002100001500043700001700058700001500075700001500090700001600105245015800121300001000279490000700289022003200296       1999                            d1 aA. Hansell1 aJ. Hollowell1 aT. Nichols1 aR. McNiece1 aD. Strachan00aUse of the General Practice Research Database (GPRD) for respiratory epidemiology: a comparison with the 4th Morbidity Survey in General Practice (MSGP4)  a413-90 v54  a0040-6376 (Print) 0040-6376