Reliability and validity of motivation for sexual health.

The Health Self-Determinism Index-Sexual (HSDI-S) is a modification of the HSDI (a measure of motivation of health). Psychometric evaluation was needed to determine the usefulness of the HSDI-S as a measure of motivation of sexual health. The purpose of this study was to assess the reliability and validity of the HSDI-S. Three unique samples of HSDI-S scores were evaluated using principal component and maximum likelihood factor analyses with a Varimax rotation. Items that loaded on each of the factors were similar across all three samples. Factor analyses revealed two dimensions of the HSDI-S: self-directed and partner-directed motivation, which is discussed within the context of relationships. The ranges of internal consistency reliability coefficients across the samples were satisfactory for the HSDI-S (.74-.82) and for the two dimensions (.66-.77). Reliability and construct validity of the HSDI-S across three diverse samples was supported.