00470nas a2200169   4500000000100000000000100001008004100002100001300043700001500056700001600071700001900087700001600106245014600122300001200268490000600280022001400286       2016                            d1 aS. Price1 aS. Stapley1 aE. Shephard1 aK. Barraclough1 aW. Hamilton00aIs omission of free text records a possible source of data loss and bias in Clinical Practice Research Datalink studies? A case-control study  ae0116640 v6  a2044-6055