Study designs of evaluations included in the review
Prospective controlled trials were eligible. Prospective randomised controlled trials (RCTs) of the following designs were included: crossover; parallel group; and time series with multiple treatment arms. Retrospective study designs, case series and case reports were excluded.
Specific interventions included in the review
Comparisons of oral docusate sodium or docusate calcium with a control treatment were eligible. Duration of docusate treatment ranged from 20 to 26 days and dose for docusate sodium ranged from 60 mg OD to 100 mg BID, and for docusate calcium from 240 mg OD to 240 mg BID. Control therapy consisted of placebo or no treatment. Dose escalation was not practised. Co-interventions included other laxatives (including enemas and suppositories) prescribed for both treatment groups or for the docusate group only. Compound medications containing docusate were excluded.
Participants included in the review
Adults described as chronically ill or in-patients in a chronic care facility and who had pre-existing constipation or risk factors for constipation were eligible. In the included studies, where the prevalence of constipation was reported, patients were either classified as constipated using self-reports or chart stool records. Definitions of constipation included: chronic functional constipation (not defined); patients on some form of bowel medication; and chronic functional constipation and dependent on laxatives. Settings included a free-standing retirement center, a chronic disease hospital, the nursing home unit of a veterans' medical center, and a chronic medical service in a hospital.
Outcomes assessed in the review
Efficacy of treatment was assessed by stool consistency (classified as 1 = watery to 5 = extremely hard; soft, normal or hard; or graded A = watery to E = enema) stool frequency, (mean stools/patient/week), or the use of other laxatives. Patient satisfaction measures were excluded.
How were decisions on the relevance of primary studies made?
The search strategy was devised and executed by a single reviewer. Two unblinded reviewers inclusion independently assessed all potentially eligible studies for inclusion with disagreements resolved by consensus.