Reliability and Validity of the Minnesota Multiphasic Personality Inventory – 2 – Restructured Form (MMPI-2-RF) in Spine Surgery and Spinal Cord Stimulator Samples

Abstract

It is not uncommon for patients to report diminished outcomes as a result of spine surgery or a spinal cord stimulator implant. Presurgical psychological evaluations are increasingly used to identify patients at increased risk for such outcomes and use of personality assessment instruments in these evaluations provides incremental information beyond a clinical interview and medical chart review. This investigation explores the psychometric properties of the Minnesota Multiphasic Personality Inventory–2–Restructured Form (MMPI–2–RF) in a sample of spine surgery patients (n = 810) and in a sample of spinal cord stimulator patients (n = 533). Results indicated that MMPI–2–RF substantive scale scores are reliable, with evidence of good convergent and discriminant validity in both samples. Incorporating the MMPI–2–RF as part of the presurgical evaluation of spine surgery and spinal cord stimulator patients can provide meaningful insight into patients’ functioning and help guide pre- and postsurgical treatment in these settings.

Disclosure of interest

Yossef Ben-Porath is a paid consultant to the MMPI–2–RF publisher, the University of Minnesota and distributor, Pearson. As coauthor of the MMPI–2–RF, he receives royalties on sales of the test.

Notes

¹Correlations between MMPI–2–RF Validity Scale scores and the PASSS domains for the two samples are reported in Tables S4 and S5. Although the MMPI–2–RF authors do not recommend relying on the tests’ validity indicators to assess substantive domains, these correlations illustrate that, as would be expected, scores on the MMPI–2–RF inconsistency scales are largely unrelated to psychological functioning, whereas scores on the overreporting indicators (with the expected exception of Fp-r) are to some extent confounded with psychological dysfunction (necessitating the use of higher cutoffs to identify overreporting), and that L-r scores are largely unrelated to dysfunction, whereas K-r scores are confounded with good psychological adjustment. A detailed discussion of these confounds and their implications for MMPI–2–RF interpretation is provided by Ben-Porath (2012).

Additional information

Funding

This study was partially funded through a grant from the University of Minnesota Press to Andrew R. Block.