# Table 3 The probability of remaining at work for at least three, six and nine years

Variable Over 3 years Over 6 years Over 9 years
(n = 119) (n = 92) (n = 59)
1. Age at the time of CABG
≤ 50 LR = 6.54 LR = 3.25 LR = 2.42
50 – 54 LR = 3.80 LR = 1.24 (LR = 0.20)
≥ 55 LR = 0.68 LR = 0.37 (LR = 0.01)
2. Postoperative cardiac symptoms
No LR = 1.11   LR = 1.08
Yes LR = 0.51   LR = 0.51
3. Height
< 175 LR = 0.59 LR = 0.58
175 – 179 LR = 1.43 LR = 1.80
180- LR = 6.29 LR = 2.13
4. Being married
No LR = 3.51 LR = 1.60 LR = 1.14
Yes LR = 0.88 LR = 0.93 LR = 0.98
5. Diagnosed DM
No LR = 0.92 LR = 1.03 LR = 1.04
Yes LR = 2.59 LR = 0.80 LR = 0.70
6. Participation in household work
Daily   LR = 1.25 LR = 1.26
Less often   LR = 0.58 LR = 0.51
Precision of the model
False-Positive 10 18 15
False-Negative 9 17 13
Sensitivity 55% 63% 82%
Specificity 92% 82% 78%
Correct predictions 86% 75% 80%
1. In this model, the individual probability of remaining at work (calculated one year postoperatively) is as follows:
2. The patient's likelihood ratio (LR) of each of six characteristics is multiplied. The greater LR, the better is the possibility of remaining at work. If the total LR is greater than 1.00, the probability of remaining at work is more than 50% for the given time (3 y, 6 y, or 9 y). Patients in age groups marked in parenthesis may remain at work for over the age of 60.
3. LR may be expressed as probability as follows: p = 100 * LR/(1+LR).