Data from study and actual activity at time of the study in 1995–6
| Activity | Cohort study (a) | Cohort projection—that is, “met incident need” (b)=(a) × 4 | Activity as % of OP referrals with possible CHD (÷by row 3) | Total actual activity 1995/6 (c) | “Met incident need” activity as % of 1995/6 total activity =(c)÷(b) | Implied “met prevalent need” activity =(c)−(b) |
| 1 GP referrals to outpatients | 107 | 428 | 41 | — | — | — |
| 2 Emergency admissions to outpatients | 154 | 616 | 59 | — | — | — |
| 3 Total referrals to outpatients | 261 | 1044 | 100 | — | — | — |
| 4 Exercise ECG | 146 | 584 | 56 | 677 | 86 | 93 |
| 5 Angiograms | 26 | 104 | 10 | 235 | 44 | 131 |
| 6 Final diagnostic CHD Group | 162 | 648 | 62 | — | — | — |
| 7 CABG | 10 | 40 | 4 | 87 | 46 | 47 |
| 8 PTCA | 6 | 24 | 2 | 29 | 83 | 5 |