Randomised controlled trial of efficacy of teaching patients with bipolar disorder to identify early symptoms of relapse and obtain treatment

British Medical Journal, Jan 16, 1999 by Alison Perry, Nicholas Tarrier, Richard Morriss, Eilis McCarthy, Kate Limb

Manic and depressive relapses were treated as independent outcomes because both the experimental and control treatments differed qualitatively for mania and depression. Time to relapse was plotted on event curves, which were analysed with the log rank test. The highly skewed data on relapse and treatment were analysed using [chi square] tests, Mann-Whitney U tests, and median differences with 95% confidence intervals. Data on relapse were complete except for one patient who died of ischaemic heart disease in the experimental group before the first assessment at six months. Scores on the patient's previous assessment were substituted when data on the social function scale were missing. Changes in the dam from the social functioning interview were almost normally distributed. They were examined using mean differences with 95% confidence intervals and factorial analysis of variance with the experimental treatment as the between subjects factor.

Results

Figure 1 shows the flow of subjects recruited to the study. The study was carried out between March 1994 and April 1997. Table 1 shows that demographic data and baseline variables were not significantly different between the experimental and control groups. There were no clinically important age and sex differences between study subjects and refusers (mean age 43 (SD 15) years, 39/57 (68%) women). Percentage agreement (interrater reliability) between a psychiatrist (RM) and the three research assistants using the standardised psychiatric interview[13] to rate the presence or absence of 70 current or past psychiatric episodes was 95% (kappas 0.84, 0.93, and 0.94).

Table 1 Demographic and clinical characteristics at baseline. Values are numbers (percentages) of patients unless stated otherwise

                                           Experimental   Control
                                              group        group
Variable                                     (n=34)       (n=35)

Mean (SD) age (years)                      44 (13)        45 (11)
Women                                      23 (68)        24 (69)
Prescribed lithium                         23 (68)        25 (71)
Contact with carer for [is greater or
  equal to] 10 h/week                      23 (68)        21 (60)
Married or cohabiting                      22 (65)        21 (60)
White ethnic origin                        30 (88)        33 (94)
Education over 16 years old                16 (47)        13 (37)
Employed                                    9 (26)         6 (17)
Median duration of illness
  (range) (years)                          11 (2-41)      12 (2-34)
Type of bipolar illness:
  I(*)                                     30 (88)        33 (94)
  II([dagger])                              4 (12)         2 (6)
Median No of bipolar episodes (range)       6 (2-25)       5 (2-17)
Median No of psychiatric admissions
  (range)                                  5 (1-21)       5 (0-19)
Mean (SD) No of weeks since last relapse   25 (16)        25 (18)
Personality disorder                        3 (9)          4 (11)
Other psychiatric disorder:([double
  dagger])                                  7 (21)         6 (17)
Prescribed mood stabilising drugs          30 (88)        31 (89)