Changes over time in study characteristics
| 1998–2010 (n=26) | 2011–2013 (n=31) | 2014–2015 (n=43) | 2016–2017 (n=71) | Test for trend, P value | |
| QALY as unit of health benefit, % | 42.3 | 64.5 | 81.4 | 83.1 | <0.0001 |
| First author at Chinese institution, % | 38.5 | 73.3 | 67.4 | 78.9 | 0.0002 |
| Quality score (cost-per-QALY studies), mean | 4.59 | 4.95 | 4.95 | 5.27 | – |
| Quality score (cost-per-DALY studies), mean | 4.43 | 4.60 | 4.81 | 5.04 | – |
DALY, disability-adjusted life-year; QALY, quality-adjusted life-year.