Table 4.

Proportion of deaths with a cause recorded in CPRD primary care data (N = 600 for each 3-year band)

How cause of death is recorded in primary care	Years 2001–2003	Years 2004–2006	Years 2007–2009	Accuracy (95% CI)
Transcribed death certificate entry (e.g. 1a Heart failure, 1b Acute myocardial infarction)
Read codes	46 (7.7%)	103 (17.2%)	112 (18.7%)	59% (52%, 65%)
Free text	32 (5.3%)	41 (6.8%)	47 (7.8%)	53% (44%, 63%)
Explicit cause of death (e.g. Cause of death: myocardial infarction)
Read codes	26 (4.3%)	47 (7.8%)	36 (6.0%)	30% (22%, 40%)
Free text	16 (2.7%)	17 (2.8%)	16 (2.7%)	55% (40%, 69%)
Cause of death implied by diagnosis dated on or after date of death
Read codes	140 (23.3%)	79 (13.2%)	52 (8.7%)	44% (37%, 51%)
Free text	69 (11.5%)	67 (11.2%)	76 (12.7%)	40% (34%, 46%)
No cause of death in CPRD	271 (45.2%)	246 (41.0%)	261 (43.5%)	–