Zeng, Y., Cheng, A. S., & Chan, C. C. (2016). Meta-analysis of the effects of neuropsychological interventions on cognitive function in non–central nervous system cancer survivors. Integrative Cancer Therapies, 15, 424–434. 

DOI Link

Purpose

STUDY PURPOSE: To examine the effects of cognitive training and cognitive rehabilitation interventions on cognitive function in adults with non-central nervous system cancers

TYPE OF STUDY: Meta-analysis and systematic review

Search Strategy

DATABASES USED: PubMed, PsycInfo, China Academic Journals Full-text Database
 
INCLUSION CRITERIA: Controlled clinical trials of cognitive training (primarily individual-based) or cognitive rehabilitation (primarily group-based) interventions in adult subjects diagnosed with non-central nervous system cancers aged 18 years or older. Randomized, controlled trials (RCTs) and non-RCTs that used any control condition were included. Outcomes included objective or self-reported measures of cognitive function. Publications from January 2010 to September 2015 were included.
 
EXCLUSION CRITERIA: Studies of adult survivors of pediatric cancers

Literature Evaluated

TOTAL REFERENCES RETRIEVED: 107 initially retrieved and screened after eliminating duplicates
 
EVALUATION METHOD AND COMMENTS ON LITERATURE USED: Cochrane Risk of Bias Assessment Tool used to evaluate quality of evidence. After calculating heterogeneity (I2) among studies, meta-analysis was used to calculate weighted mean differences (WMDs) for the same instruments or standardized mean differences (SMDs) for different instruments for the cognitive outcomes.

Sample Characteristics

  • FINAL NUMBER STUDIES INCLUDED = 9 included in the meta-analysis
  • TOTAL PATIENTS INCLUDED IN REVIEW = 410 included in the meta-analysis
  • SAMPLE RANGE ACROSS STUDIES: 22–98 patients 
  • KEY SAMPLE CHARACTERISTICS: The mean age in studies ranged from 45–75 years. Cancer diagnoses were breast (n = 4) or mixed non-CNS (n = 5) cancers. Two studies were not randomized. Five studies had sample sizes of less than 40.

Phase of Care and Clinical Applications

PHASE OF CARE: Multiple phases of care
 
APPLICATIONS: Elder care

Results

Three studies tested cognitive training, and six studies tested cognitive rehabilitation. Most studies used waitlist control groups, with intervention durations of one to six months. Outcomes included verbal and/or visual memory (n = 8), executive function (n = 4), attention (n = 6), processing speed (n = 2), language (n = 1), and self-reported cognitive function (n = 9). A moderate-to-high risk of bias was found across studies. Statistical heterogeneity ranged from 0% to 96%. By outcome measure, the number of studies included in each part of the meta-analysis ranged from two to five. Cognitive training and cognitive rehabilitation interventions improved immediate (n = 2, WMD = 7.58, 95% confidence interval [CI] = [0.07, 15.09], p < 0.05) and delayed (n = 2, WMD = 10.85, 95% CI [4.19, 17.51], p = 0.001) memory at post intervention. Both types of interventions improved verbal learning at post intervention (n = 5, SMD = 0.5, 95% CI [0.19, 0.81], p = 0.001) and follow-up (n = 3, SMD = 0.58, 95% CI [0.19, 0.98], p = 0.004). Cognitive training interventions improved self-reported cognitive function at post intervention (n = 2, SMD = 0.52, 95% CI [0.06, 0.98], p = 0.03) and follow-up (n = 2, SMD = 0.54, 95% CI [0.08, 1], p = 0.02).

Conclusions

The meta-analysis indicated that both cognitive training and cognitive rehabilitation interventions may improve objectively measured memory and verbal learning, whereas cognitive training interventions may improve self-reported cognitive function. No treatment effects were found for executive function, attention, processing speed, or language. The weaknesses of this meta-analysis limit its usefulness in determining the effects of these types of interventions on cognitive function.

Limitations

  • Limited number of studies included
  • High heterogeneity
  • Low sample sizes

Nursing Implications

Individual-based cognitive training and group-based cognitive rehabilitation may improve objectively measured memory and verbal learning, as well as self-reported cognitive function, in adult survivors of cancer. Because of the small number and weaknesses of included studies, the benefits of these interventions are unclear.

Legacy ID

6237