How Concurrent Services Obscured Detection of Intervention Benefits: Part 2: Secondary Analysis of the PREP Trial for Frail Older Adults and Family Caregivers.

Family caregivers frequently use health and social services to support their caregiving. In evaluating care-giving interventions, however, researchers rarely examine the influences of such concurrent services on intervention effectiveness. In this Part 2 secondary analysis of data from the Oregon Health & Science University/Kaiser Permanente Northwest Region Family Care Study, we examined the moderating influences of concurrent services on intervention effectiveness. The Family Care Study was a randomized controlled trial to evaluate the preparedness, skill, enrichment, and predictability (PREP) intervention with caregivers of frail older adults referred for skilled home health. Compared with control caregivers receiving usual home health care (n = 103), PREP intervention caregivers (n = 104) reported greater improvements in family care (effect size, d = 0.58). We conducted follow-up analyses to determine whether PREP was differentially effective depending on whether dyads received concurrent Social Health Maintenance Organization (SHMO) services, concurrent hospice services, or neither. In the 55% of dyads not receiving SHMO or hospice, we found that PREP's effects were large compared to usual care (d = 1.16, p < 0.001). PREP's effects were not significant for dyads receiving concurrent SHMO or hospice services. Results highlight the strong benefits of hospice for control dyads, but reveal difficulties in evaluating intervention effectiveness when dyads receive concurrent services. [Research in Gerontological Nursing, 16(2), 71-83.].