Structured data sets were collected from 547 patients (286 from Study 1 and 261 from Study 2) in 12 centers across Poland. 369 patients were eligible for further analysis.
Demographics
The demographic data are presented in Table 1. The mean age was 68 years (range 26-94), with equal representation of men and women. 42% were hospice, 31% - home care, and 26% - ambulatory patients. Most of them (80%) had non-gastrointestinal (most common: lung 25.7%, breast 11.4%, prostate 7.6%), 6.5% – colorectal, and 12% – other gastrointestinal cancer diagnosed.
The study groups did not differ from each other regarding age, sex, and primary site of the tumor. In Study 1, most of the patients were in-patient, while in Study 2, most were home care patients, which catered for a balanced representation of these subpopulations. Patients in in-patient hospices were statistically in worse performance status than those at-home care or in palliative ambulatory patients (p<0.05).
There was a positive correlation between ECOG performance status and age. The older the patient, the worse status was.
61% of all patients received strong opioids, and the mean oral morphine equivalent of opioids (OME) was 99 mg/day. The differences between the study groups were statistically significant. 56% of patients in Study 1 received strong opioids, and the mean OME was 87 mg/day (median 60), while 71% of patients in Study 2 were treated with opioids, and the mean OME was 113 mg/day (median 95), p = 0.004.
Diet modification to ease bowel movements was implemented in approximately 45% of patients. The same proportion of patients had used oral laxatives in the last seven days. 29% used suppositories (bisacodyl, glycerol, or both). Referring to interventional procedures,12% of patients received an enema, and in 5% of patients, manual stool evacuation was performed.
The symptoms of constipation
Figure 1 presents the mean values of symptoms of constipation, with the twelve items composing the PAC-SYM tool. Some items, like cramps, rectal burning, or rectal bleeding, were reported relatively rarely. On the other hand, incomplete BM, too hard or too small stools, and straining are frequently observed by patients.
The frequency of SBM was negatively correlated with ECOG. The worse the performance status, the less frequency of SBM was observed (p < 0.05).
The correlation between the objective criteria of constipation and the patient’s assessment of constipation
The two objective measures: the last SBM and frequency of SBM, and the two patient-reported measures: the difficulty of defecation and BFI, were well correlated positively or negatively with each other (p < 0.05) with logical direction (Table 2). The higher frequency of SBM, the less difficult defecation, and lower BFI were. On the opposite, the more days from the last SBM, the more difficult defecation and higher BFI were. The patient-reported criteria, i.e., the difficulty of defecation and BFI, were correlated with each other, with Spearman’s rank coefficient r = 0.94 (p < 0.05). Their relation is linear. The mild difficulty of defecation (the mean score 1 in [0-4] scale) corresponds to the mean BFI 2 in [0-10] scale, and moderate (the mean score 2) corresponds to the mean BFI 4.5.
The cut-offs for objective criteria for moderate to the severe difficulty of defecation
There is a linear relationship between the difficulty of defecation and mean frequency of SBM, days since last SBM, and the necessity of laxatives (Figure 2). On average, patients assessed the difficulty of defecation as moderately disturbed when the time since the last SBM was 2 days. A frequency of SBM 3 per week was associated with the mild to moderate difficulty of defecation, and if it was <3 per week, the difficulty of defecation became severe (mean > 2.71 (95% CI 2.62-2.81).
Any necessity of laxatives was associated with the worsening of ease of defecation. When laxatives were used often (2 in [0-4] scale), the difficulty of defecation ranged from moderate to significant.
Opioid-induced constipation
There were no statistically significant differences for any results between subgroups of patients treated with opioid analgesics and not taking the opioids.