Table 2. Approaches to analysis reported in 31 papers identified in the review that used Cox regression.
Description of method | Number of papers | |
Choice of timescale | time in study | 22 |
age | 9 | |
Analysis model | Cox weighted | 20 |
Cox unweighted | 11 | |
Weights used in Cox model | Prentice | 10 |
Barlow | 7 | |
not stated | 3 | |
Robust standard errors used | 17 | |
Proportional hazards assumption | 12 |