The relationship between the Wiggins' PSY scale and length of hospitalization: a re-examination.

Peteroy, Pirrello, and Adams' (1982) findings on two Wiggins content scales, DEP and PSY, were re-examined. In contrast to Peteroy et al.'s results, both scales were found to relate significantly to length of psychiatric hospitalization (LOH) when a larger, more heterogeneous sampling (N = 362) was employed, together with a wider range of LOH values. This study demonstrates how attention to relevant sampling parameters in predictive validity studies can help to ensure that the utility of measures such as PSY is not misjudged.