Table 5

Clinical factors: quality of improvement associated with lithium maintenance treatment

Variable Superior (n=181) Inferior (n=179) F test P
Response is rated superior or inferior by per cent improvement in the proportion of time ill being above or below the approximate median of 75%; for analysis of variance, d.f.=1; 358; for χ2, d.f.=1. A multiple logistic regression with superior response based on percentage of time ill showed: longer first interval on lithium > shorter index recovery on lithium > shorter time before starting lithium > more episodes per year before lithium (overall model: χ2=91.2, P <0.0001).
1.Months between end of the first and start of the second lifetime episodes.
2.Months to recovery from episode at which lithium started.
3.Months from end of index episode at start of lithium to start of first recurrence during lithium maintenance.
Onset age (years (s.d)) 30.9 (12.8) 27.4 (11.0) 7.99 0.005
First euthymic interval (months (s.d.))1 16.7 (45.5 35.2 (66.2) 9.64 0.002
Episodes/year before treatment (s.d.) 2.14 (2.24) 1.52 (1.87) 7.66 0.006
Percentage time ill before treatment (s.d.) 53.2 (31.3) 38.2 (28.1) 22.8 <0.0001
Latency: onset to treatment (years (s.d.)) 7.31 (8.02) 9.30 (8.34) 5.35 0.021
Index recovery (months (s.d.))2 2.21 (1.86) 4.15 (4.90) 24.8 <0.0001
First on-lithium interval (months (s.d.))3 45.4 (44.7) 13.6 (23.9) 70.5 <0.0001
Serum lithium concentration (mmol/l (s.d.)) 0.57 (0.11) 0.66 (0.14) 50.5 <0.0001