Is the Test of Premorbid Functioning a Valid Measure for Maori in New Zealand

This study examined whether scores on the Test of Premorbid Functioning (TOPF) accurately predicted current performance on the Wechsler Adult Intelligence Scale (Fourth Edition; WAIS-IV) in a sample of 284 neurologically normal Maori (age range 16-90yrs). Participants were recruited from seven areas of New Zealand's (NZ) North and South Islands, as well as from different iwi (tribes) to ensure a representative sample. The hypothesis that the TOPF would not accurately predict current WAIS-IV performance was supported. TOPF scores only accounted for between 32-36% of the variance in WAIS-IV Full Scale Intelligence Quotient (FSIQ) scores as compared to the over 50% typically reported in overseas studies. The TOPF accurately predicted FSIQ categorisation for just over half the sample. These findings suggest that the TOPF is not a valid measure of premorbid functioning for Maori in New Zealand.