Cost-effectiveness analyses
SENSITIVITY
Secondary care resource use for the STAR follow-up period was only available for the 226 participants who had consented to have information extracted from their medical records. Throughout the four-year time horizon (Table 
Resource use during the STAR trial and follow-up at four years*Two sites do not have an A&E department so the total numbers of patients for each group are differentUsing a multiple imputed dataset for the 337 participants showed that the adjusted long stay admission costs were still the main cost driver for differences in NHS costs, in favour of the intervention arm (Table 
Inpatient costsThe difference had attenuated over time from -£737 in the first year after randomisation to -£339 in years one-four, culminating in an overall cost difference of -£1075 (-£3084, £933) (Table 
Cost-effectiveness results at 4 years4982(3727,6237)2.60(2.49,2.70)5983(4164,7801)2.47(2.31,2.63)-1001(-3238,1236)0.13(-0.06,0.32)3525(-990, 8039)All variables are adjusted for hospital site and baseline BPI subscores. Additionally, QALYs are adjusted for baseline utility
Sensitivity analyses (cost effectiveness)5073(3807,6340)2.65(2.54,2.75)6120(4472,7768)2.53(2.36,2.69)-1046(-3099, 1006)0.12(-0.08,0.32)3458(-1025, 7940)4869(3707,6031)2.55(2.44,2.65)5982(4184,7600)2.42(2.27,2.58)-1023(-3033, 987)0.12(-0.07,0.30)3392(-931, 7716)4331(3426,5236)2.60(2.48,2.70)5197(3881,6513)2.47(2.32,2.63)-866(-2460, 728)0.12(-0.07,0.30)3170(-1012, 7351)4954(4052, 5857)2.54(2.41,2.66)5876(4639,7112)2.45(2.28,2.63)-1007(-2533, 519)0.12(-0.05,0.29)3330(-480, 7142)This resulted in adjusted mean NHS costs (including the costs of the STAR care pathway) being -£1001 (95% CI -£3238, £1236) lower in the intervention arm. The adjusted difference in mean QALYs of 0.13 (95% CI -0.06, 0.31) also favoured the intervention arm. This led to an incremental net monetary benefit of £3,525 (95% CI -£990 to £8039) at a £20,000/QALY willingness-to-pay threshold, and the probability of being cost-effective at this threshold of 0.94 (Fig. The sensitivity analyses showed the initial analyses to be robust (Table 