Table 3.
Overview of parameter estimates included in QALY regression analysis before and after backward elimination of candidate explanatory variables
| Variable | Parameter | Estimate (s.e.) before reduction | p value | Estimate (s.e.) in final model | p value |
|---|---|---|---|---|---|
| Intercept | — | 0.313 (0.016) | — | 0.315 (0.016) | — |
| Treatment | — | — | 0.045 | — | 0.024 |
| IDeg | 0.008 (0.006) | — | 0.005 (0.002) | — | |
| IGlar | 0 | — | 0 | — | |
| Gender | — | — | 0.003 | — | 0.003 |
| Female | −0.006 (0.002) | — | −0.006 (0.002) | — | |
| Male | 0 | — | 0 | — | |
| Region | — | — | 0.016 | — | 0.017 |
| Asia | −0.024 (0.010) | — | −0.023 (0.010) | — | |
| Europe | −0.015 (0.009) | — | −0.015 (0.009) | — | |
| Japan | −0.024 (0.012) | — | −0.024 (0.012) | — | |
| North America | −0.021 (0.009) | — | −0.021 (0.009) | — | |
| South Africa | −0.014 (0.010) | — | −0.013 (0.010) | — | |
| South America | 0 | — | 0 | — | |
| Insulin naïve | — | — | 0.329 | — | — |
| No | −0.006 (0.006) | — | — | — | |
| Yes | 0 | — | — | — | |
| Trial | — | — | 0.006 | — | <0.0001 |
| T2D BOT (3579) | −0.007 (0.006) | — | −0.007 (0.003) | — | |
| T2D BB (3582) | −0.009 (0.008) | — | −0.015 (0.003) | — | |
| T1D BB (3583) | 0.001 (0.009) | — | −0.005 (0.004) | — | |
| T2D BOT Asia (3586) | 0.014 (0.009) | — | 0.010 (0.008) | — | |
| T2D BOT Flex (3668) | 0.002 (0.007) | — | −0.004 (0.005) | — | |
| T2D BOT U200 (3672) | 0 | — | 0 | — | |
| Treatment by trial interaction | — | — | 0.875 | — | — |
| IDeg × T2D BOT | −0.002 (0.007) | — | — | — | |
| IDeg × T2D BB | −0.001 (0.007) | — | — | — | |
| IDeg × T1D BB | −0.001 (0.008) | — | — | — | |
| IDeg × T2D BOT Asia | −0.006 (0.008) | — | — | — | |
| IDeg × T2D BOT Flex | −0.009 (0.008) | — | — | — | |
| IDeg × T2D BOT U200 | 0 | — | — | — | |
| IGlar × T2D BOT | 0 | — | — | — | |
| IGlar × T2D BB | 0 | — | — | — | |
| IGlar × T1D BB | 0 | — | — | — | |
| IGlar × T2D BOT Asia | 0 | — | — | — | |
| IGlar × T2D BOT Flex | 0 | — | — | — | |
| IGlar × T2D BOT U200 | 0 | — | — | — | |
| Age | — | −0.0005 (0.0001) | <0.0001 | −0.0005 (0.0001) | <0.0001 |
| Baseline utility | — | 0.712 (0.012) | <0.0001 | 0.712 (0.012) | <0.0001 |
p values are based on type III sums of squares test.
BB, basal–bolus; BOT, basal supported oral therapy; IDeg, insulin degludec; IGlar, insulin glargine; QALY, quality-adjusted life years; s.e., standard error; T1D, type 1 diabetes mellitus; T2D, type 2 diabetes mellitus.