Types of studies

Randomised controlled trials and quasi‐randomised trials comparing reflexology for constipation with sham treatment, conventional treatment or no treatment will be considered for inclusion. Controlled before and after studies or interrupted time series studies will also be considered for inclusion. All eligible trials will be included regardless of language and publication type. There will be no language restrictions.

Types of participants

Male or female patients of any age with chronic idiopathic constipation receiving care in a variety of healthcare settings (hospital, community) in treatment or follow‐up will be included. Chronic idiopathic constipation can be defined using the Rome I, II or II criteria. Idiopathic constipation according to the Rome III criteria (Longstreth 2006) consists of two or more of the following symptoms for at least 3 months:
1. straining during at least 25% defecations;
2. lumpy or hard stools in at least 25% defecations;
3. sensation of incomplete evacuation for at least 25% defecations;
4. sensation of anorectal obstruction or blockage in at least 25% defecations;
5. manual manoeuvres to facilitate at least 25% of defecations (e.g. digital evacuation, support of the pelvic floor);
6. fewer than 3 defecations per week;
7. loose stools are rarely present without the use of laxatives; and
8. insufficient criteria for a diagnosis of irritable bowel syndrome (IBS).

To avoid missing studies that do not utilize Rome criteria the American College of Gastroenterology Chronic Constipation Task Force definition of chronic constipation will also be utilized. The Task Force defines chronic constipation as, "unsatisfactory defecation characterized by infrequent stools, difficult stool passage or both (Brandt 2005)." Constipation secondary to the use of constipating medication or to conditions such as diabetes mellitus, hypothyroidism, tumour, anal fissure as well as acute constipation will be excluded.

Types of interventions

Studies of reflexology treatment for chronic constipation will be considered for inclusion. Reflexology treatments need to be carried out by a qualified practitioner.

Types of outcome measures

Selection of studies

Two authors (SW & CN) will independently review potentially relevant studies to determine if they meet the pre‐specified inclusion criteria. Any disagreement between authors will be resolved by consensus and if necessary by consultation with the third author.

Data extraction and management

A standardized data extraction sheet will be developed to record data on: study quality, study setting, participants (age and sex; how diagnosis was confirmed; inclusion and exclusion criteria), interventions (type of reflexology, administration, duration, regimen of controlled intervention), outcome measures, attrition, intention to treat analysis, duration of follow‐up and the type and number of any reported adverse events. Two authors (SW & CN) will independently extract the data from each study. Any disagreement will be resolved by discussion and consensus with a third author (JG).

Assessment of risk of bias in included studies

The full text of all 'eligible' studies will be obtained for independent review by both authors. The methodological quality of each study will be assessed and where necessary the study authors will be contacted for missing data or clarification of the published data.

The Cochrane risk of bias tool (Higgins 2008) will be used to assess the quality of randomised controlled trials. Factors to be assessed include:

1. sequence generation (i.e. was the allocation sequence adequately generated?);

2. allocation sequence concealment (i.e. was allocation adequately concealed?);

3. blinding (i.e. was knowledge of the allocated intervention adequately prevented during the study?);

4. incomplete outcome data (i.e. were incomplete outcome data adequately addressed?);

5. selective outcome reporting (i.e. are reports of the study free of suggestion of selective outcome reporting?); and 

6. other potential sources of bias (i.e. was the study apparently free of other problems that could put it at a high risk of bias?).

A judgement of 'Yes' indicates low risk of bias, 'No' indicates high risk of bias, and 'Unclear' indicates unclear or unknown risk of bias. Disagreements will be resolved by consensus. Study authors will be contacted when insufficient information is provided to determine risk of bias. A validated instrument (Downs 1998) will be used for measuring the quality of non‐randomised studies.

Measures of treatment effect

The extracted data from the original studies will be used to construct 2 x 2 tables (e.g. clinical improvement versus no improvement for reflexology versus sham). The relative risk (RR) with 95% confidence intervals (95% CI) will be calculated for each outcome. The number needed to treat (NNT) and risk difference (RD) will be calculated where appropriate. An intention‐to‐treat analysis will be used. For continuous variables, the weighted mean difference (WMD) or standardised mean difference with 95% CI will be calculated.

Dealing with missing data

The authors of the included studies will be contacted to obtain any missing data.

Assessment of heterogeneity

Heterogeneity will be assessed using the chi‐square test (a P value of 0.10 will be regarded as statistically significant). The I² statistic will be used to estimate the degree of heterogeneity. This measure describes the percentage of total variation across studies that results from heterogeneity rather than chance. A value of 25% is considered to indicate low heterogeneity, 50% moderate heterogeneity and 75% high heterogeneity (Higgins 2003). Sources of heterogeneity will be investigated using a graphic display. The log RR and its 95% confidence interval (CI) will be calculated and plotted for each trial. These plots will be examined to identify any possible outliers as well as to explore any trends in outcome due to differences in methodology, patient population or treatment regimes.

Assessment of reporting biases

Potential publication bias will be investigated using the funnel plot or other corrective analytical methods (Egger 1997). A linear regression approach to measure funnel plot asymmetry on the natural logarithm scale of the odds ratio will be used.

Data synthesis

Data will be analysed using Review Manager (RevMan 5.0.21). Data from individual trials will be combined for meta‐analysis if the interventions, patient groups and outcomes are sufficiently similar (to be determined by consensus). Data will not be pooled for meta‐analysis if a high degree of heterogeneity is detected (i.e. I²> 75%). A fixed effects model will be used to pool data in the absence of heterogeneity. A random effects model will be used if significant heterogeneity is detected. The pooled RR and 95% CI will be calculated for dichotomous outcomes. For continuous outcomes the pooled WMD or SMD and 95% CI will be calculated as appropriate.

Subgroup analysis and investigation of heterogeneity

If a sufficient number of randomised trials are identified, the following subgroups analyses will be performed:
1. treatment duration (less than six weeks or more than six weeks); and
2. duration of disease (less than 5 years, 5 to 10 years, more than 10 years).

Sensitivity analysis

A sensitivity analysis will be carried out to determine if the findings from the primary analysis are changed by incorporating different trials in the analysis. This will be done by varying the inclusion criteria and repeating the analysis with the new data set. In addition, the effect of including randomised controlled trials reported only in abstracts and in languages other than English will be examined. Furthermore, if a sufficient number of randomised trials are identified, a sensitivity analysis to explore the influence of trial quality on effect estimates will be performed.