Normative data for the Brief Symptom Inventory for mature and independent living adults
The percentage of the population in the United States that is 65 and older is rapidly increasing. It is important that assessment instruments, when used with older individuals, have norms available that are applicable to the particular age group of the individual being assessed. The purpose of this study was to determine raw score means for mature and independent-living adults who completed the Brief Symptom Inventory. Relevant norms and symptom dimensions of the BSI that hold confounding items for individuals 65 and older were determined. Four hundred eighty-nine individuals 65 and older (322 females, 167 males, mean age of 75.91) living independently completed the Brief Symptom Inventory and the Demographic and Activity Questionnaire. Participants were recruited from senior citizen centers administered by various cities in the North Texas area, residential retirement facilities, and churches.
The raw mean scores on the nine primary symptom dimensions were compared against similar scores from a normative sample of younger adult non-patients and younger adult psychiatric outpatients. These scores were also compared to two other groups of older adults who completed the Brief Symptom Inventory and whose raw score means were published by Hale, Cochran and Hedgeperth (1984) and De Leo, Frisoni, Rozzini, and Trabucchi (1993).
Statistical analysis found that the study sample raw score means were most similar to the raw score means obtained by Hale et al. (1984). The study sample was found to be dissimilar to De Leo et al.'s (1993) sample and was also quite dissimilar to the published Brief Symptom Inventory raw score means for adult psychiatric outpatients. Males in the study sample had statistically significant raw mean scores on the Somatization, Obsessive-Compulsive, Interpersonal-Sensitivity, Depression symptom, and Psychoticism symptom dimensions than the published Brief Symptom Inventory raw score means for male adult non-patients. Females in the study group had statistically significant raw score means on the Somatization, Obsessive-Compulsive, Anxiety, Hostility, and Psychoticism symptom dimensions than the published Brief Symptom Inventory raw score means for adult female non-patients. Factor analysis found that six factors: Obsessive-Compulsive, Depression, Somatization, Paranoid Ideation, Anxiety (combining Panic and Phobic), and a distinct factor incorporating Psychoticism and Phobic Anxiety, more accurately assess this age group than the nine symptom dimensions of the Brief Symptom Inventory. Additional research was suggested to determine the validity and reliability of these new factors. As mature and elderly independent-living adults report higher levels of symptom distress, it is recommended that age appropriate raw score means be used when using the Brief Symptom Inventory with individuals 65 and older.