Milbury 2013.
Study characteristics | ||
Methods | Randomised controlled trial Intention‐to‐treat analysis: ITT was undertaken Loss to follow‐up: numbers reported in flowchart and reasons reported in text |
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Participants |
Inclusion criteria Females aged 18 years and over diagnosed with stages I‐IIIA breast cancer, proficient in English who had received chemotherapy 6 to 60 months previously, were currently using hormonal therapies, reporting cognitive impairment post‐treatment and lived within 2 hours driving distance of institution. Exclusion criteria Documented diagnosis of thought disorder (e.g. schizophrenia) or neurological injury or a MMSE of less than or equal to 23 or metastatic/recurrent cancer or prior regular meditation practice. Participants were identified from institution's electronic medical records and posted invitations to the study. Randomisation method: minimisation, an adaptive randomisation method evenly balanced according to age, time since diagnosis, menopausal status, receptor status, of disease, surgical procedure, type of hormone treatment stage other medications with possible cognitive effects, and baseline self‐report cognitive function scores. Participants: 47 (I: 23/ C: 24) Cancer site(s): Breast cancer stages I (I: 6/ C: 6); II (I: 13/ C: 13); III (I: 4/ C: 5) Age: I: mean = 53.0 (SD = 6.6); C: mean = 54.1 (SD = 8.6) Sex: Female Treatment history: All patients received chemotherapy and were between 6 to 60 months post‐chemotherapy and current use of hormonal therapy. Receipt of radiotherapy (I: 17/ C: 19) and; surgery (I: 20/C: 24) Co‐morbidities: None reported Education: Some college or higher (I: 22/ C: 18) Socio‐economic status: None reported Cognitive impairment at baseline: Participants had to have cognitive impairment relating to chemotherapy assessed by 4 items of the FACT‐Cog Country: USA |
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Interventions |
Definition: Tibetan Sound Meditation (TSM) delivered by trained meditation instructors To assess the feasibility and efficacy of TSM to improve cognitive functioning and QoL Duration: Twice weekly (one‐hour) sessions over a 6‐week period Components: Breathing, awareness and concentration techniques. Visualisation and sound exercises with three, separate but inter‐related stages and associated cognitive activity including: stage one acknowledging, cleansing and releasing negative thoughts; stage two identifying and retrieving a positive supportive quality and; stage 3 integrating quality into everyday life. Techniques Social support (unspecified): group setting for delivery of intervention Instruction on how to perform the behaviour: supervision, CD and written instructions Demonstration of the behaviour: supervision, CD and written instructions Behavioural practice/rehearsal: attendance at session and home practice Generalisation of target behaviour: transference of practice from supervised sessions to home Reduce negative emotions: meditation 'releasing negative thoughts', breathing Framing/reframing: identifying a positive, supportive quality Materials: CD, printed instructions Theoretical basis/mechanism: Mind‐body practice may target cognitive impairment via stress reduction and regulation of immune system. Setting: Instructor‐led sessions at institution, participants also encouraged to practice at home. Personnel: Meditation instructors Comparison: Wait‐list control |
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Outcomes | Self‐report outcomes were assessed at baseline, post‐intervention and one‐month post‐intervention. Objective cognitive function outcomes were assessed at baseline and one‐month post‐intervention in order to counteract practice effects. Subjective cognitive function: *FACT‐Cog (version 3) 4 domains: Perceived cognitive impairments; Impact on QoL; Comments of others; Perceived cognitive abilities. Objective cognitive function: *Digit Symbol Test to assess visuo‐motor co‐ordination, processing speed and attention; *Digit Span Test to assess working memory and attention; *RAVLT to assess verbal memory and; *COWAT to assess verbal fluency Secondary outcomes: SF‐36 (physical and mental component summary scores) to assess health‐related QoL; FACT‐spiritual to assess spiritual QoL; CES‐D to assess depression; BFI to assess fatigue; PSQI to assess sleep disturbances; weekly, brief evaluation of classes to assess satisfaction with intervention. Adherence: Class attendance and frequency of home practice Safety issues: None reported Adverse effects: None reported |
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Notes | *Primary outcome measures in study. Participants were rewarded with a small gift to the value of $25 for completing each assessment. |
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Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (selection bias) | Low risk | "...participants were randomly assigned to either the TSM or WLC group by a form of adaptive randomization called minimization [63] so that the groups were evenly balanced according to age, time since diagnosis, menopausal status, receptor status, stage of disease, surgical procedure, type of hormone treatment (e.g. tamoxifen vs. AIs), other medications with possible cognitive effects (e.g. Effexor), and baseline subjective reports of cognitive function (FACT‐Cog total score)." Pg 2356 |
Allocation concealment (selection bias) | Unclear risk | No further information reported about randomisation procedure: likely that with the use of minimisation in a small, single‐centred study, allocation could be predicted if previous allocation is known. |
Blinding of participants and personnel (performance bias) All outcomes | Low risk | Unable to blind participants to a TSM intervention. |
Blinding of outcome assessment (detection bias) Objective outcomes | Unclear risk | No details reported. |
Incomplete outcome data (attrition bias) All outcomes | Unclear risk | "One person who dropped out from control prior to Time point 3 assessment was unaccounted for. All other drop‐outs were accounted for." Pg 2358 Intention‐to‐treat analysis undertaken, no description of how missing values were imputed. |
Selective reporting (reporting bias) | Unclear risk | Raw means, SDs and effect sizes only were reported for all outcomes in tables 2 and 3. No P values or confidence interval reported, we relied on author's reporting of significant group differences in text in relation to intervention effectiveness. |
Baseline imbalances in cognition scores Objective outcomes | Unclear risk | "There were also no significant differences in patient characteristics (except for ethnicity) or any of the objective and subjective outcome variables (see Table 1)." pg 2357. However, cognition scores are not reported in Table 1 and no P values or confidence intervals are reported in the Tables 2 and 3 where information relating to these outcomes are found. |
Baseline imbalances in cognition scores Subjective outcomes | Unclear risk | "There were also no significant differences in patient characteristics (except for ethnicity) or any of the objective and subjective outcome variables (see Table 1)." pg 2357 However, cognition scores are not reported in Table 1 and no P values or confidence intervals are reported in the Tables 2 and 3 where information relating to these outcomes are found. |
Validity of cognitive function measures Objective outcomes | Unclear risk | None reported. |
Validity of cognitive function measures Subjective outcomes | Unclear risk | None reported. |
Reliability of cognitive function measures Objective outcomes | Unclear risk | None reported. |
Reliability of cognitive function measures Subjective outcomes | Unclear risk | None reported. |