Measuring anankastic personality traits

The authors validate a 20 item scale designed to measure anankastic (obsessive) personality traits: the Mini-Inventory of Anankastic Personality Traits, 2nd version (MIAPT-2).

The answers of a sample of 418 subject of both genders obtained from the general population were used to analyze construct validity (factorial analysis), its alpha reliability and its internal consistency through the item/total correlations and the two halves test. An additional sample of 22 medical students was used to analyze the concurrent validity of the scale (external criterion: the Maudsley Obsessional-Compulsive Inventory) and the temporary reliability with the test-retest method. After this, the total scores of the instrument and the factorial scores were standardized and distributed into percentiles.

The scale shows good concurrent validity (r = 0.67; p < 0.000) and construct validity (56 % of the total of the variance explained by the factorial analysis) as well as a good internal consistency through the item/total correlations (all p = 0.000) and two halves test (r = 0.71; p < 0.000; with the Spearman-Brown correction R= 0.83). The alpha reliability of the scale (alpha = 0.84), and the test-retest (r = 0.69; p < 0.000) are high.

The validated MIAPT-2 shows good validity and reliability to evaluate anankastic personality traits. The authors include an appendix with the scale and the standardization of its total and factorial scores distributed into percentiles to be used in clinical and general population samples.