Partner Interdependence and Life-Threatening Illness: Factors Associated with Dyadic Adjustment

1. Partner Interdependence and Life-Threatening Illness: Factors Associated with Dyadic Adjustment Betsy L. Fife, MSN, PhD Senior Research Scientist Michael T. Weaver, PhD, FAAN Professor and Director of Statistical Services William Cook, PhD Maine Medical Center American Cancer Society, #RSGBP-5-012-01-CPPB Center of Excellence in Nursing Education Pedagogical Expertise of Faculty 2009 - 2012

2. Purpose • To explore the impact of a life-threatening illness on the adaptation of committed partners as indicated by the quality of adjustment within the relationship

3. Research Questions • Relative to adjustment within the relationship, what is the impact of each partner on the other? • Do the effects on adjustment between partners vary across the trajectory as dynamics of the illness change? • Is the level of impact from each partner on dyadic adjustment similar, or does one partner have a greater effect than the other?

4. Model of Dyadic Adjustment to Cancer & Bone Marrow Transplantation CONTEXTUAL FACTORS Treatment Factors Time from Diagnosis Recipient Symptomatology Type BMT Cancer Diagnosis Person/Dyad Factors Recipient Gender Recipient Age Recipient Education RESOURCE AVAILABILITY Personal Resources Personal Control Spirituality Perceived Social Support Health Care Professionals Family Support STRESS RESPONSE Coping Strategies Avoidance Dyadic Coping Emotional Response Negative Affect OUTCOME Dyadic Adjustment

5. Sample – 192 Dyads • BMT Recipient • Male: 133 (69.6%) • Age: 50.6 (12.8) • Caucasian: 192 (100%) • Education • 8th Grade or Less: 2 (1%) • High School / Voc: 86 (46%) • Some College+: 78 (43%) • Graduate School: 19 (10%) • Caregiver • Female: 139 (72%) • Age: 50.5 (11.4) • Caucasian: 192 (100%) • Education • 8th Grade or Less: 2 (1%) • High School / Voc: 77 (40%) • Some College+: 84 (44%) • Graduate School: 29 (15%)

6. Analysis • Change in dyadic adjustment (DAS) over time • General linear mixed model (SAS 9.2 PROC MIXED) • Model Effects: Partner (Recipient/Caregiver), Time, Partner*Time • Inter-relationship of partner and recipient dyadic adjustment • Actor-Partner Interdependence Model (APIM - Kenny, Kashy, & Cook, 2006: Dyadic Data Analysis) • Path analysis (MPlus version 6.11) using MLR estimator • Exploratory development of parsimonious model with adequate fit • Begin with all parameters free; added constraints while evaluating model fit • Factors influencing dyadic adjustment for recipient & caregiver • Separate General Linear models for recipient and caregiver at each of the 4 time points (SAS 9.2 PROC GLM) • Hierarchical addition of covariate blocks to test R2 change for addition of (1) stress response, (2) resource availability, (3) contextual factors • .05 level of significance • Statistical model assumptions evaluated – no remediation necessary

7. Results: Change in DAS over Time • Slope for DAS change over time similar for recipient & caregiver • Partner*Time interaction p=0.588 • Mean DAS similar across time points • Time effect p=0.160 • Recipient mean DAS (118.4) was higher than caregiver (114.6) • F=17.2; DF=1,175; p<.001 • Means for recipient & caregiver similar to healthy married dyads (114.8) & higher than for divorced dyads (70.7)

8. APIM Model Results (paths p < .05 shown) .156; .027 .156; .027 CG DASTOT T1 CG DASTOT T2 CG DASTOT T3 .765; <.001 .765; <.001 CG DASTOT T4 .765; <.001 -.370; .001 .173; .008 .186; .001 .223; .009 PT DASTOT T1 PT DASTOT T2 PT DASTOT T3 PT DASTOT T4 .412; .001 .412; .001 .412; .001 .296; <.001 .208; .001 .296; <.001 Model Fit: 2=4.46; DF=6; p=.614; CFI=1.00; RMSEA=.000

9. Results: Factors Influencing Recipient DAS • Full models had R2 from .31 - .49 with p<.001 • Stress Response • Associated with DAS at all time points • R2 from .26 - .45 • Availability of Resources | Stress response • T2-T4: Semipartial R2 .041 - .16; p .03 - <.001; T1: N/S • Contextual | Availability of Resources & Stress Response • T1: Semipartial R2 .047, p=.02; T2-T4: N/S • Independent associations in full models: • Partner-Related Coping: T1-T4, p<.001 • Health Professional Support: T2-T4, p<.04

10. Results: Factors Influencing Caregiver DAS • Full models had R2 from .40 - .56 with p<.001 • Stress Response • Associated with DAS at all time points • R2 from .37 - .52 • Availability of Resources | Stress response • T1,T2,T4: Semipartial R2 .06 - .09; p .001 - <.001; T3: N/S • Contextual | Availability of Resources & Stress Response • T1 – T4: N/S • Independent associations in full models: • Partner-Related Coping: T1-T4, p<.001 • Spirituality: T1, T2, T4, p<.04 • Avoidance coping (inverse association): T3, T4, p<.001 • Health professional support: T2 & T4, p<.03 • Symptom interference: T3 only, p<.03

11. Conclusions • Use of the APIM Model allowed examination of the interdependence between the caregiver and the BMT recipient. • The most dependent partner, the recipient, had the strongest partner effect. • The caregiver partner experienced unrelenting distress, which exceeded that of the recipient. • Given the increasing extent to which family members are required to provide homecare for seriously ill patients raises concern for the mental health of family members and for family integrity.