Effectiveness Not Established

Yoga

for Cognitive Impairment

Yoga is an ancient Eastern science that incorporates stress-reduction techniques such as regulated breathing, visual imagery, and meditation, as well as various postures. Hatha yoga is one type of yoga. Yoga has been examined as an intervention for anxiety, depression, chemotherapy-induced nausea and vomiting, hot flashes, cognitive impairment, sleep-wake disturbances, pain, and fatigue in patients with cancer. It has also been examined as an intervention for caregiver strain and burden.

Systematic Review/Meta-Analysis

Chan, R.J., McCarthy, A.L., Devenish, J., Sullivan, K.A., & Chan, A. (2015). Systematic review of pharmacologic and non-pharmacologic interventions to manage cognitive alterations after chemotherapy for breast cancer. European Journal of Cancer, 51, 437–450. 

Purpose

STUDY PURPOSE: To review what is known about the effectiveness of pharmacologic and nonpharmacologic interventions for managing self-reported or objective cognitive impairment associated with chemotherapy for breast cancer
 
TYPE OF STUDY: Systematic review

Search Strategy

DATABASES USED: MEDLINE, EBSCOhost, CINAHL, and Cochrane CENTRAL
 
KEYWORDS: Extensive list of terms, including keywords relevant to the receipt of chemotherapy, randomized controlled trials (RCTs), and cognitive impairment
 
INCLUSION CRITERIA: Prospective RCTs of pharmacologic or nonpharmacologic interventions to manage cognitive impairment during or after chemotherapy for cancer; subjective or objective measurement of cognitive function; published in English
 
EXCLUSION CRITERIA: Inclusion of patients with brain tumors or metastases; inclusion of patients not receiving chemotherapy; less than half of patients in sample diagnosed with breast cancers; unpublished RCTs; letters to the editor; retrospective chart reviews

Literature Evaluated

TOTAL REFERENCES RETRIEVED: 29
 
EVALUATION METHOD AND COMMENTS ON LITERATURE USED: Retrieved references were assessed by type of cancer (13 removed), cognitive impairment as an outcome (two removed), and confirmation of RCT (one removed). The Cochrane Collaboration risk of bias criteria were used to evaluate the final set of studies on randomization, blinding, and outcome reporting. Although effect sizes or relative risk were calculated for individual studies, a meta-analysis was not done because of the heterogeneity of the interventions and outcome measures.
 

Sample Characteristics

  • FINAL NUMBER STUDIES INCLUDED = 13
  • TOTAL PATIENTS INCLUDED IN REVIEW = 1,138
  • SAMPLE RANGE ACROSS STUDIES = 20–210 patients
  • KEY SAMPLE CHARACTERISTICS: Most studies included only women with breast cancer. All participants received chemotherapy with or without radiation therapy or hormonal therapy. Most participants were aged about 55 years. The majority of studies were conducted in the United States. Most outcomes were evaluated in the short-term (i.e., less than three months).

Phase of Care and Clinical Applications

PHASE OF CARE: Late effects and survivorship

Results

Risk of bias was high in 11 studies but unclear in  two studies that evaluated psychostimulants.

Pharmacologic interventions: No improvements in cognitive function were found using psychostimulants (four studies) or ginkgo biloba. Patients reported better cognitive function using epoetin alfa with doses titrated for hemoglobin levels (p < 0.05). However, a death caused by a cerebrovascular accident was noted.

Nonpharmacologic interventions: Small-group memory training improved self-reported cognitive function, and both memory and speed of processing after small-group training improved immediate and delayed recall (p < 0.05). Home-based online executive function training improved verbal function and attention (p < 0.05). Speed-feedback therapy during biking improved executive and motor function (p < 0.05). Cognitive behavioral therapy-based interventions (two studies), Tibetan sound meditation, and hatha yoga did not improve cognitive function.

Conclusions

The pharmacologic studies reviewed did not support the use of psychostimulants or ginkgo biloba to improve cognitive function after chemotherapy for breast cancer. Epoetin alfa was not recommended for practice because of safety concerns. The nonpharmacologic studies reviewed provided some evidence that cognitive training and speed-feedback therapy might improve cognitive function for breast cancer survivors.

Limitations

The risk of bias was high for most studies. Therefore, although positive results were found, well-designed, prospective RCTs need to be completed to confirm these findings. It is unclear how sustainable the positive results of the cognitive training and exercise interventions might be because follow-up was limited to less than three months.

Nursing Implications

This systematic review provided limited support for cognitive training and structured exercise to improve cognitive function after chemotherapy for breast cancer. Cognitive training is currently categorized as likely to be effective for cognitive impairment.

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Research Evidence Summaries

Derry, H.M., Jaremka, L.M., Bennett, J.M., Peng, J., Andridge, R., Shapiro, C., . . . Kiecolt-Glaser, J.K. (2014). Yoga and self-reported cognitive problems in breast cancer survivors: A randomized controlled trial. Psycho-Oncology. Advance online publication. 

Study Purpose

To determine the effects of yoga on self-reported cognitive function

Intervention Characteristics/Basic Study Process

Certified yoga instructors led two 90-minute yoga group classes per week for 12 weeks. Each group contained 4–20 participants. Hatha yoga poses targeting relaxation, mindful breathing, chest opening, spinal extension, upper-body strength, and mobility were predetermined for each of the 24 sessions, and protocol drift was monitored. Pamphlets describing the poses from the classes and a yoga DVD were provided for home practice. Participants recorded weekly home and class time to determine dose effects. Participants who missed a class were called to improve adherence. Waitlist control participants continued regular activities and were directed not to begin yoga practice until after their final assessments. Measures were assessed before the behavioral intervention, immediately after the 12-week intervention, and three months after the intervention.

Sample Characteristics

  • N = 200  
  • MEAN AGE = 51.6 years (SD = 9.2 years) 
  • FEMALES (%): 100
  • KEY DISEASE CHARACTERISTICS: Breast cancer survivors in stages 0-IIIA between two months and three years after the completion of primary and adjuvant treatment (except for antiestrogen therapy).
  • OTHER KEY SAMPLE CHARACTERISTICS: The sample was an average of 17.3 (SD = 8.1) months since diagnosis and 10.9 ( SD = 7.9) months since treatment. The sample was highly educated; 69.5% of participants were college graduates or had postgraduate education. 81% of participants were postmenopausal.

Setting

  • SITE: Single-site    
  • SETTING TYPE: Multiple settings    
  • LOCATION: Ohio State University Cancer Center in Columbus, Ohio, a yoga studio, and participants’ homes

Phase of Care and Clinical Applications

  • PHASE OF CARE: Late effects and survivorship

Study Design

Randomized, waitlist-controlled trial

Measurement Instruments/Methods

  • Breast Cancer Prevention Trial (BCPT) Symptom Checklist–Cognitive Problems subscale
  • Center for Epidemiological Studies–Depression (CES-D) scale
  • Beck Anxiety Inventory (BAI)
  • Pittsburgh Sleep Quality Index (PSQI)
  • Medical Outcomes Study Short-Form survey (SF-36) Energy Subscale
  • Community Healthy Activities Model Program for Seniors questionnaire (CHAMPS) (physical activity)
  • Fasting blood samples for lipopolysaccharide-stimulated cytokine levels (IL-6, IL-1 beta, TNF-alpha)

Results

At baseline, the average self-reported cognitive impairment was slight to moderate and did not differ between groups. Overall group and group-by-time effects were found (p < .05, both). Although no differences were found immediately after the 12-week intervention, the intervention group reported significantly less cognitive impairment than controls three months after the intervention ended (p < .01). However, these effects did not remain after controlling for symptom covariates (e.g., anxiety, depression, fatigue, sleep quality). Participants with more daily yoga practice (mean of 29 minutes) reported less cognitive impairment postintervention through three months (p = .011), and participants with less daily yoga practice (mean of 18 minutes) or no daily yoga practice did not report these changes. This dose response remained when controlling for symptom covariates. At three months, the intervention group reported more physical activity than controls (p = .032). Cytokine levels did not predict changes in self-reported cognitive impairment.

Conclusions

A 12-week, group Hatha yoga intervention provided by a trained instructor may improve self-reported cognitive impairment in breast cancer survivors. This effect may be mediated by improvements in co-occurring symptoms. Practicing yoga for at least 30 minutes per day may be required for a significant improvement over time in cognitive impairment.

Limitations

  • Risk of bias (no blinding)
  • Risk of bias (no appropriate attentional control condition)
  • Findings not generalizable
  • Intervention expensive, impractical, or training needs
  • Other limitations/explanation: Participants were not blinded to their group assignment. The nonspecific effects of social support or attention may have been responsible for improvements in symptoms given the lack of a control group. It was unknown what component of the intervention (e.g., physical activity, mindfulness) was active. The sample was mostly white and well-educated, limiting generalizability. The intervention would require training for facilitators to maintain fidelity. Cognitive function was measured only with self-report instruments. The duration of the intervention effect is unknown because of the lack of long-term (> 3 months) follow-up assessments.

Nursing Implications

A group Hatha yoga class delivered by a trained facilitator may improve cognitive impairment for breast cancer survivors. However, more research with a longer follow-up period is warranted to determine whether the intervention is effective, what component of the intervention is active, and whether yoga is practical for implementation in practice.

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Janelsins, M.C., Peppone, L.J., Heckler, C.E., Kesler, S.R., Sprod, L.K., Atkins, J., . . . Mustian, K.M. (2015). YOCAS©® Yoga reduces self-reported memory difficulty in cancer survivors in a nationwide randomized clinical trial: Investigating relationships between memory and sleep. Integrative Cancer Therapies, 15, 263–271. 

Study Purpose

To investigate the effect of a combined hatha and restorative yoga intervention on memory in cancer survivors and to explore relationships between memory and sleep

Intervention Characteristics/Basic Study Process

YOCAS©® (Yoga for Cancer Survivors) is an instructor-guided standardized program that incorporates movement emphasizing restorative poses, breathing exercises, and mindfulness exercises. The intervention was offered twice a week in the late afternoon or evening over 75 minutes for a total of eight sessions. Although all the group trainers were Registered Yoga Alliance Teachers, they were also required to complete a training session, reviewing a detailed YOCAS©® manual to facilitate standardization across sites.

Sample Characteristics

  • N = 328   
  • MEAN AGE = 54.62 years
  • AGE RANGE = 26–72 years
  • MALES: 4%, FEMALES: 96%
  • CURRENT TREATMENT: Hormonal therapy in 53% of sample
  • KEY DISEASE CHARACTERISTICS: Various cancers but predominantly breast cancer (77%)
  • OTHER KEY SAMPLE CHARACTERISTICS: Of the sample, 82% had a partial college education or more. Seventy-four percent of women were postmenopausal.

Setting

  • SITE: Multi-site  
  • SETTING TYPE: Outpatient    
  • LOCATION: 12 cities within the United States

Phase of Care and Clinical Applications

PHASE OF CARE: Late effects and survivorship

Study Design

Secondary analysis of a randomized, clinical trial

Measurement Instruments/Methods

  • MD Anderson Symptom Inventory (MDASI)—primary outcome was one item regarding perceived memory.
  • Pittsburgh Sleep Quality Index (PSQI)—primary outcome was global sleep quality.

Results

At baseline, the average score on the MDASI indicated only a mild level of perceived memory problems overall. Although both groups continued to report memory problems as being mild, a significant decrease (p < 0.05) was observed in patients who completed the intervention. This difference continued to be significant when controlling for differences in age, gender, educational level, past treatment regimen, current hormonal therapy, baseline memory, and baseline sleep scores. Of note, those who received the intervention also had improved sleep (p < 0.05), which accounted for approximately 26% of the improvement in memory (p = 0.039).

Conclusions

Although yoga appeared to decrease perceived memory problems, this outcome was based on a single item of the MDASI. Further longitudinal studies designed specifically to measure the effect of yoga on cognitive function as measured by both objective and subjective measures are warranted.

Limitations

  • Risk of bias (no blinding)
  • Measurement validity/reliability questionable

 

Nursing Implications

Although this study suggested that yoga may improve patients’ perception of memory problems, some of the benefit was because of better sleep.

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