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Selection Bias Introduced by Neuropsychological Assessments

Published online by Cambridge University Press:  02 December 2014

Robert Olson ,
Maureen Parkinson  and
Michael McKenzie
Robert Olson*
Affiliation:
Vancouver Cancer Centre, Radiation Therapy Program, BC Cancer Agency Division of Radiation Oncology and Developmental Radiotherapeutics, University of British Columbia, Vancouver Harvard School of Public Health, Boston, MA, USA
Maureen Parkinson
Affiliation:
Fraser Valley Cancer Centre, Department of Patient and Family Counseling, BC Cancer Agency, Surrey, British Columbia, Canada
Michael McKenzie
Affiliation:
Vancouver Cancer Centre, Radiation Therapy Program, BC Cancer Agency Division of Radiation Oncology and Developmental Radiotherapeutics, University of British Columbia, Vancouver
*
600 West 10th Avenue, Vancouver, British Columbia, V5Z 4E6, Canada. E-mail: [email protected].
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Abstract

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Objective:

Two prospective studies in patient with brain tumours were performed comparing the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). The first assessed their feasibility and the second compared their diagnostic accuracy against a four-hour neuropsychological assessment (NPA). The introduction of the NPA decreased accrual and retention rates. We were therefore concerned regarding potential selection bias.

Methods:

Ninety-two patients were prospectively accrued and subsequently divided into three categories: a) no NPA required b) withdrew consent to NPA c) completed NPA. In order to quantify any potential bias introduced by the NPA, patient demographics and cognitive test scores were compared between the three groups.

Results:

There were significant differences in age (p<0.001), education (p=0.034), dexamethasone use (p=0.002), MMSE (p=0.005), and MoCA scores (p<0.001) across the different study groups. Furthermore, with increasing involvement of the NPA, patients' cognitive scores and educational status increased, while their age, dexamethasone use, and opioid use all decreased. Individuals who completed the NPA had higher MoCA scores than individuals who were not asked to complete the NPA (24.7 vs. 20.5; p < 0.001). In addition, this relationship held when restricting the analyses to individuals with brain metastases (p < 0.001).

Conclusions:

In this study, the lengthy NPA chosen introduced a statistically and clinically significant source of selection bias. These results highlight the importance of selecting brief and well tolerated assessments when possible. However, researchers are challenged by weighing the improved selection bias associated with brief assessments at the cost of reduced diagnostic accuracy.

Type
Research Article
Information
Canadian Journal of Neurological Sciences , Volume 37 , Issue 2 , March 2010 , pp. 264 - 268
Copyright
Copyright © The Canadian Journal of Neurological 2010

References

1. Chang, EJ, Wefel, JS, Maor, MH, Hassenbush, SJ III, Mahajan, A, Lang, FF, et al. A pilot study of neurocognitive function in patients with one to three new brain metastases initially treated with stereotactic radiosurgery alone. Neurosurg. 2007;60(2):277–84.CrossRefGoogle ScholarPubMed
2. Taphoorn, MJB, Klein, M. Cognitive deficits in adult patients with brain tumours. Lancet Neuro. 2004;3(3):159–68.CrossRefGoogle ScholarPubMed
3. Herman, MA, Tremont-Lukats, I, Meyers, CA, Trask, DD, Froseth, C, Renschler, MF, et al. Neurocognitive and functional assessment of patients with brain metastases: a pilot study. Am J Clin Oncol. 2003;26(3):273–9.CrossRefGoogle ScholarPubMed
4. Mehta, MP, Shapiro, WR, Glantz, MJ, Patchell, RA, Weitzner, MA, Meyers, CA, et al. Lead-in phase to randomized trial of motexafin gadolinium and whole-brain radiation for patients with brain metastases: centralized assessment of magnetic resonance imaging, neurocognitive, and neurologic end points. J Clin Oncol. 2002;20(16):3445–53.CrossRefGoogle ScholarPubMed
5. Meyers, CA, Hess, KR, Yung, WKA, Levin, VA. Cognitive function as a predictor of survival in patients with recurrent malignant glioma. J Clin Oncol. 2000;18(3):646–50.CrossRefGoogle ScholarPubMed
6. Meyers, CA, Smith, JA, Bezjak, A, Mehta, MP, Liebmann, J, Illidge, T, et al. Neurocognitive function and progression in patients with brain metastases treated with whole-brain radiation and motexafin gadolinium: results of a randomized phase III trial. J Clin Oncol. 2004;22(1):157–65.CrossRefGoogle ScholarPubMed
7. Meyers, CA, Hess, KR. Multifaceted end points in brain tumor clinical trials: cognitive deterioration precedes MRI progression. Neuro-oncol. 2003;5(2):89–95.CrossRefGoogle ScholarPubMed
8. Patel, RR, Mehta, MP. Targeted therapy for brain metastases: improving the therapeutic ratio. Clin Cancer Res. 2007;13(6):1675–83.CrossRefGoogle ScholarPubMed
9. Sherman, AM, Jaeckle, K, Meyers, CA. Pretreatment cognitive performance predicts survival in patients with leptomeningeal disease. Cancer. 2002;95(6):1311–6.CrossRefGoogle ScholarPubMed
10. Meyers, CA, Brown, PD. Role and relevance of neurocognitive assessment in clinical trials of patients with CNS tumors. J Clin Oncol. 2006;24(8):1305–9.CrossRefGoogle ScholarPubMed
11. Sherman, AM, Jaeckle, K, Meyers, CA. Pretreatment cognitive performance predicts survival in patients with leptomeningeal disease. Cancer. 2002;95(6):1311–6.CrossRefGoogle ScholarPubMed
12. Meyers, CA, Wefel, JS. The use of the mini-mental state examination to assess cognitive functioning in cancer trials: no ifs, ands, buts, or sensitivity. J Clin Oncol. 2003;21(19):3557–8.CrossRefGoogle ScholarPubMed
13. Nasreddine, ZS, Phillips, NA, Bedirian, V, Charbonneau, S, Whitehead, V, Collin, I, et al. The Montreal cognitive assessment, MoCA: a brief screening tool for mild cognitive impairment. J Am Ger Soc. 2005;53(4):695–9.CrossRefGoogle Scholar
14. Folstein, MF, Folstein, SE, McHugh, PR. “Mini-mental state”: a practical method for grading the cognitive state of patients for the clinician. J Psych Res. 1975;12(3):189–98.CrossRefGoogle ScholarPubMed
15. Smith, T, Gildeh, N, Holmes, C. The Montreal cognitive assessment: Validity and utility in a memory clinic setting. Can J Psychiat. 2007;52(5):329–32.CrossRefGoogle Scholar
16. Olson, RA, Chhanabhai, T, McKenzie, M. Feasibility study of the Montreal cognitive assessment (MoCA) in patients with brain metastases. Support Care Cancer. 2008;16(11):1273–8.CrossRefGoogle ScholarPubMed
17. Olson, RA, Iverson, G, Parkinson, M, Carolan, H, Ellwood, A, McKenzie, M. Investigation of cognitive screening measures in patients with brain tumors: diagnostic accuracy and correlation with quality of life. J Clin Oncol (Meeting Abstracts). 2009;27(15S):e13000.Google Scholar
18. Weiss, DJ, Kingsbury, GG. Application of computerized adaptive testing to educational problems. J Educ Meas. 1984;21(4):361–75.CrossRefGoogle Scholar
19. Meijer, RR, Nering, ML. Computerized adaptive testing: overview and introduction. App Psych Meas. 1999;23(3):187–94.CrossRefGoogle Scholar
20. Berk, RA. An introduction to sample selection bias in sociological data. Am Sociol Rev. 1983;48(3):386–98.CrossRefGoogle Scholar
21. Jüni, P, Altman, DG, Egger, M. Systematic reviews in health care: assessing the quality of controlled clinical trials. BMJ. 2001;323(7303):42.CrossRefGoogle ScholarPubMed