Table 2. Cox proportional hazards models for incident outcome by CTI. Variable Number of events, n Model 1 Model 2 Model 3 HR 95% CI p HR 95% CI p HR 95% CI p CTI (per 1 unit) 2011 1.09 1.01-1.18 0.02 1.09 1.01-1.18 0.02 1.08 1.00-1.17 0.03 CTI quartile     Q1 (Ref) 474 Ref Ref Ref     Q2 484 1.02 0.89-1.17 0.81 1.01 0.88-1.16 0.90 1.00 0.88-1.14 0.92     Q3 508 1.07 0.93-1.21 0.35 1.04 0.91-1.19 0.55 1.03 0.91-1.16 0.58     Q4 545 1.15 1.01-1.31 0.03 1.14 1.01-1.30 0.04 1.12 1.00-1.24 0.07     P for trend 0.02 0.02 0.02 HR = hazard ratio; CI = confidence interval. Q1 represents the lowest quartile and was used as the reference group. Model 1 included no covariate adjustment; Model 2 was adjusted for demographic and lifestyle factors (sex, age, residence, marital status, education, smoking, and alcohol use); and Model 3 additionally accounted for comorbid conditions such as chronic diseases, arthritis, liver disease, asthma, kidney disease, and gastrointestinal disorders, as well as the use of anti-diabetic medication, anti-hypertensive medication, and lipid-lowering medication as covariates. The p for trend was estimated by treating the median value of each quartile as a continuous variable in the Cox regression model. Statistical significance was defined as a two-sided p < 0.05.