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. Author manuscript; available in PMC: 2015 Oct 25.
Published in final edited form as: Psychol Med. 2014 Apr 10;44(16):3455–3467. doi: 10.1017/S0033291714000804

Table 3.

Logistic regression and Cox regression analyses evaluating previous mood episodes, illness duration and age at onset as predictors of likelihood of recovery and time until recovery

Predictor b Wald OR (95% CI) p Δ R 2a
Previous depressive episode models
 Logistic regression: predicting recovery 0.07
  Treatment groupb 0.63 4.43 1.88 (1.04–3.37) 0.035
  1–9 Depressive episodesc 0.75 4.74 2.12 (1.08–4.16) 0.030
  10–20 Depressive episodesc −0.22 0.26 0.35 (0.35–1.86) 0.612
 Cox regression: predicting time until recovery 0.05
  Treatment groupb 0.40 4.72 1.49 (1.04–2.14) 0.030
  1–9 Depressive episodesc 0.43 5.06 1.53 (1.06–2.22) 0.024
  10–20 Depressive episodesc 0.21 0.53 1.23 (0.70–2.17) 0.468
Previous manic episode models
 Logistic regression: predicting recovery 0.06
  Treatment groupb 0.62 4.33 1.86 (1.04–3.32) 0.038
  1–9 Manic episodesc 0.30 0.88 1.35 (0.72–2.54) 0.349
  10–20 Manic episodesc 0.81 0.31 2.25 (0.91–5.54) 0.078
 Cox regression: predicting time until recovery 0.06
  Treatment groupb 0.36 3.74 1.43 (0.99–2.06) 0.053
  1–9 Manic episodesc 0.43 4.57 1.53 (1.04–2.27) 0.033
  10–20 Manic episodesc 0.55 5.06 1.73 (1.07–2.78) 0.025
Illness duration models
 Logistic regression: predicting recovery 0.04
  Treatment groupb 0.66 5.06 1.94 (1.09–3.45) 0.025
  Illness duration −0.01 0.47 0.99 (0.97–1.02) 0.494
 Cox regression: predicting time until recovery 0.06
  Treatment groupb 0.40 4.76 1.50 (1.04–2.15) 0.029
  Illness duration −0.02 6.29 0.98 (0.97–0.99) 0.012
Age at onset models
 Logistic regression: predicting recovery 0.04
  Treatment groupb 0.65 4.86 1.91 (1.07–3.41) 0.028
  Age at onset 0.01 0.31 1.01 (0.98–1.04) 0.575
 Cox regression: predicting time until recovery
  Treatment groupb 0.40 4.64 1.49 (1.04–2.15) 0.031 0.03
  Age at onset 0.01 1.07 1.01 (0.99–1.03) 0.301

OR, Odds ratio; CI, confidence interval.

a

R2 for logistic regressions represents Nagelkerke R2, an estimate of the increment in variance in the probability of recovery accounted for by the predictors tested. R2 for Cox regressions represents Cox–Snell R2, an estimate of the relative association between survival and the predictors tested.

b

Treatment group=intensive psychotherapy (1) versus collaborative care (0).

c

Depressive and manic episodes: dummy coded with the group with 20+ episodes coded as the reference group; therefore only coefficients relative to the reference group are presented.