Background and Aims The low-intensity monitoring protocol has been shown to be non-inferior to standard monitoring in the international randomised controlled OPTIMISTmain trial that enrolled low-risk patients (NIHSS score <10) who received thrombolysis treatment for acute ischaemic stroke. We undertook a pre-specified economic evaluation.
Methods A cost-minimisation analysis alongside OPTIMISTmain was conducted for Australia, China, Malaysia, UK, USA and Vietnam, respectively. A decision tree model comprising two arms - low-intensity care and standard care - was developed based on the trial design. State transition probabilities for each country were extracted from the trial and costs were derived from existing literature. The average 3-month costs in both arms were estimated and compared. To address uncertainty over base case results, univariate and probabilistic sensitivity analyses were performed.
Results Among the included six countries, low-intensity monitoring had the highest probability of cost-saving in China (100.0%) and UK (100.0%), followed by Australia (99.9%), USA (95.9%) and Vietnam (86.7%) as patients in the low-intensity group incurred USD239, USD133, USD647, USD943 and USD3, less direct costs than those in the standard group, respectively. In Malaysia, the intervention was unlikely to be cost-saving, but the numbers were small. Cost-saving thresholds of the monitoring cost were 1.24, 1.30, 1.26, 1.24, 1.01 and 0.91, times its base case value in Australia, China, UK, USA, Vietnam and Malaysia, respectively.
Conclusions Overall, low-intensity monitoring appears cost-saving but net cost savings are likely to be higher in countries with higher economic status.