Is a chest pain observation unit likely to be cost effective at my hospital? Extrapolation of data from a randomised controlled trial

Objectives: The ESCAPE trial showed that chest pain observation unit (CPOU) care appeared to be cost effective compared with routine care. This finding may not be generalisable to hospitals that currently admit fewer patients than the trial hospital or that require higher direct costs to provide CPOU care. This study aimed to explore these issues in sensitivity analyses and develop a nomogram to allow prediction of whether a CPOU will be cost effective in a specific hospital. Methods: Data from the ESCAPE trial was used to populate a decision analysis model comparing CPOU with routine care. Sensitivity analyses examined the effect of varying the admission rate with routine care and the direct running costs of CPOU care following which the nomogram was created. Results: CPOU care provided improved outcome (0.3936 v 0.3799 QALYs) at lower cost (478 pound v 556 pound per patient), with fewer patients admitted (37% v 54%). Mean cost of CPOU and routine care was 116 pound and 73 pound, respectively, and of inpatient hospital stay was 312 pound. The mean post-discharge cost for CPOU and routine care was 253 pound and 309 pound, respectively. Sensitivity analyses showed that CPOU care will not reduce costs at a hospital that currently admits fewer than 35% of patients, or a hospital that expects to incur direct CPOU running costs of 60 pound per patient more than the trial hospital. Conclusions: Findings of the ESCAPE trial are likely to be generalisable to most settings. The nomogram presented here can be used to predict cost effectiveness in a specific hospital.