2021-08-17
P. P. TOSKES*, K. L. CONNERY* & T. W. RITCHEY
RESULTS
Patients
Twenty-eight patients with irritable bowel syndrome were enrolled in the study. Two patients completed the study but were excluded from the analyses because of protocol violations (concomitant medications). Also excluded from the analyses were data collected from three patients who dropped out of the study for personal reasons unrelated to the medication or the study protocol. Data from 2 3 patients who completed the study as outlined in the protocol were included in the statistical analyses. Among these 23 patients were 7 males and 16 females, ranging in age from 20 to 69 years (meanfS.D. 47.5 & 16.3). Males ranged in weight from 65 to 105 kg (84f13,5) and in height from175 to188 cm (180+5).
Table 1. Treatment order, major symptom complex at entry, and overall preference among 23 patients with irritable bowel syndrome taking calcium polycarbophil (polycarbophil) and placebo in a randomized, double-blind crossover study.
Females ranged in weight from 46 to 136 kg (69f21.5) and in height from 132 to 173 cm (161f10).
Overall preference
Table 1 gives treatment order, major symptom complex, and patient overall preference for calcium polycarbophil or placebo. (The statistical analysis of overall preference was based only on those patients who expressed a preference; two patients did not express a preference for either treatment.) Upon completion of the study, 15of 2 1 patients (71%) preferred polycarbophil to placebo (P = 0.08). Calcium polycarbophil was consistently favoured over placebo within subgroups of patients (some patients are included in more than one subgroup) that were identified by diagnosis and symptom complex. As shown in Table 1, the majority of patients had a diagnosis that included constipation: among these patients, 15 of 19 (79%) preferred polycarbophil to placebo (P = 0.01). Calcium polycarbophil was favoured by all 6 patients with a diagnosis of alternating diarrhoea and constipation (P = 0.03). Patients with two more symptoms (a combination of either nausea and/or pain and/or bloating) as a feature of their irritable bowel syndrome symptom complex showed the strongest preference for calcium polycarbophil: polycarbophil was preferred by 11 (92%) of the 12 participants with multiple symptoms (P < 0.01). A cross-tabulation of preference to baseline symptoms shows that patients with bloating favoured polycarbophil more strongly than patients with no bloating (Table 2). Thirteen of the 15 (87%) patients with bloating preferred polycarbophil (P < 0.01). On the other hand, only 2 of 6 (33%) patients with no bloating chose polycarbophil.
The order of administration of polycarbophil or placebo did not affect patient preference. The hypothesis of no carryover effect was not rejected (two-sidedP > 0.60); the test was performed using the 21 patients who expressed a preference, using Fisher’s Exact Test for a 2 x 2 contingency table.
Monthly global evaluations
Table 3 shows patient monthly global evaluations of treatment efficacy (combined Period 1 and Period 2 average scores for each treatment) for all evaluable patients and for the patient subgroups identified in the previous section (patients with constipation or alternating diarrhoea and constipation, and patients with bloating or multiple symptoms). For all evaluable patients, calcium polycarbophil was rated better than placebo (P = 0.08) by global evaluation. Within the patient subgroups, the differences in rating scores between polycarbophil and placebo were similar to the differences recorded in the global evaluation for all patients.
An analysis of variance procedure demonstrated a significant interaction (P < 0.001) between patient and treatment, i.e. the differencebetween polycarbophil and placebo was not the same for all patients. When each patient's average placeboevaluation was subtracted from the corresponding average calcium polycarbophil evaluation, the nine largest differences were found among patients who preferred polycarbophil. These differences suggest that patients who preferred calcium polycarbophil perceived a greater difference between treatments than those who preferred placebo.
Patient diary assessments
The results of patient subjective assessments (combined Period 1and Period 2 average scores for each treatment) showed that, among all patients, a significant difference was found in favour of calcium polycarbophil for ease of passage (P = 0.05) (Table 4). Polycarbophil was rated better than placebo for relief of bloating, nausea, and pain, although the differences were not statistically significant. Thirteen patients with constipation and one patient with diarrhoea were selected for evaluation of stool consistency. These were patients who would be likely to have an obvious change in the consistency of their stools. No differences were found between polycarbophil and placebo for this parameter.
Adverse experiences
All reported adverse experiences were those associated with the symptoms of irritable bowel syndrome.
