Intravenous immunoglobulin in the treatment of primary trigeminal neuralgia refractory to carbamazepine: a study protocol[ISRCTN33042138]

Table 2 Secondary outcome parameters.

Variable	Groups compared	Scale	Time period of evaluation	Time compared with
Improvement	A	PGIC	α	Week preceding treatment
Reduction in carbamazepine	A	Fraction of patients with a reduction of dose; absolute reduction of dose	α	As above
Pain	A	11-point numeric rating scale	α	As above
Pain	A	Categorical verbal pain scale	α	As above
Pain	A	Average number of attacks	α	As above
Number of patients to cross over	A	Fraction of patients enrolled in crossover period	At crossover	-
Time in study	B	Number of days	Crossover period	Main study period
Improvement	B	PGIC	α	Same time periods post crossover, as judged against the week preceding treatment.
Pain	B	11-point numeric rating scale	α	Same time periods post crossover
Pain	B	Categorical verbal pain scale	α	As above
Pain	B	Average number of paroxysms	α	As above
Quality of life	A	COOP/WONCA charts, SF-36	β	-
Quality of life	B	PACIS, COOP/WONCA charts, SF-36	β	PACIS: immediately before first treatment

A: Patients with placebo and patients with IVIG, B: Patients post crossover and same patients before crossover, α: Average of values from study day 13–19 and average of values during 7 days before termination/ completion of study, β: First two weeks following (main or crossover) treatment and last two weeks before the end of (main or crossover) study for a particular patient, PACIS: one time point measurement at day 14 following treatment and at the day of the end of (main or crossover) study. PGIC: Patient Global Impression of Change Scale [17]; SF-36: Medical Outcomes Study 36-Item Short Form [18]; COOP/WONCA: Dartmouth Primary Care Cooperative Information Project charts for adults [19]; PACIS: Perceived Adjustment to Chronic Illness Scale [20].

ISSN: 1471-2377