Risk factor | Study | n | Follow-up | Results (95% CI; P value) | Analyses adjusted for* | Outcome assessment tool, scale range |
Outcome: global challenging behaviour (BPSD) or problem behaviour (four studies) | ||||||
Emotional distancing/boundary ambiguity | Caron et al36 | 60 | 12 m | Corr 0.27 (P<0.001) (overall) | NR | BEHAVE-AD, 0–75 |
Non-adaptive coping | de Vugt et al46 | 69 | 6m | MD NR (P=0.007) | g, s, ct | NPI, 1–144 |
69 | 12 m | MD NR (P=0.019) | g, s, ct | |||
Avoidant attachment | Perren et al41 | 68 | 24 m | MD 0.23 (P<0.05) | NR | NPI, 1–144 |
Expressed emotion | Vitaliano et al44 | 77 | 15–18 m | MD 1.9 (0.77 to 3.04; P<0.001) | NR | SCB, 0–8 |
Outcome: psychotic symptoms (three studies) | ||||||
Mutuality | Ball et al33 | 171 | 24 m | MD −0.1 (−0.24 to 0.04; P>0.05) (delusions) | a, g, d, e | NPI, 1–12 |
Ball et al33 | 171 | 24 m | MD −0.04 (−0.16 to 0.08; P>0.05) (hallucinations) | a, g, d, e | ||
Emotional distancing/boundary ambiguity | Caron et al36 | 60 | 12 m | Corr 0.30 (P<0.001) (paranoia) | NR | BEHAVE-AD, 0–75 |
Non-adaptive coping | de Vugt et al46 | 69 | 12 m | MD NR (P>0.05) (psychosis) | g, s | NPI, 1–24 |
Outcome: depression (five studies) | ||||||
Mutuality | Ball et al33 | 171 | 24 m | MD −0.43 (−0.80 to -0.06; P<0.05) | a, g, d, e | HAM-D, 0–68 |
Quality of relationship | Burgener and Twigg20 | 70 | 18 m | Corr 0.22 (P>0.05) | NR | Cornell, 0–38 |
Emotional distancing/boundary ambiguity | Caron et al36 | 60 | 12 m | Corr 0.01 (P>0.05) | NR | BEHAVE-AD, 0–75 |
Expressed emotion | Vitaliano et al44 | 77 | 15–18 m | MD 2.00 (−0.31 to 4.31; P>0.05) | NR | HAM-D, 0–68 |
Cohesion quantity | Wright et al43 | 14 | 6m | Corr −0.302 (P>0.05) | NR | Zung, 0–270 |
Quality | 14 | 6m | Corr −0.387 (P>0.05) | NR | ||
Affection quantity | Wright et al43 | 14 | 6m | Corr −2.41 (P>0.05) | NR | |
Quality | 14 | 6m | Corr −0.038 (P>0.05) | NR | ||
Tension quantity | Wright et al43 | 14 | 6m | Corr 0.533 (P<0.01) | NR | |
Quality | 14 | 6m | Corr −0.288 (P>0.05) | NR | ||
Outcome: other | ||||||
Non-adaptive coping | de Vugt et al46 | 69 | 12 m | MD NR (P=0.512) (apathy) | g, s, ct | NPI, 1–48 |
Non-adaptive coping | de Vugt et al46 | 69 | 12 m | MD NR (P=0.005) (hyperactivity) | g, s, ct | NPI, 1–60 |
Mutuality | Morgan et al34 and Kunik et al32 | 171 | 24 m | MD −0.42 (−0.64 to 0.20; P<0.001) HR 0.63 (0.45 to 2.87; P=0.006) (aggression) | NR | CMAI, 0–156 |
Emotional distancing/boundary ambiguity | Caron et al36 | 60 | 6m | Corr 0.15 (P>0.05) (anxiety) | NR | BEHAVE-AD, 0–75 |
*Prespecified key confounders: a, age; d, dementia severity; g, gender; s, socioeconomic status. All other confounders: ct, carer type; e, ethnicity.
HR > 1 Indicates increased risk, HR < 1 indicates decreased risk . OR > 1 indicates increased odds of outcome, OR < 1 Indicates decreased odds of outcome.
BEHAVE-AD, Behavioural Pathology in Alzheimer’s Disease Rating Scale; BPSD, Behavioural and Psychological Symptoms of Dementia; CMAI, Cohen Mansfield Agitation Inventory; Corr, correlation (This is a number between −1 to +1 and indicates the degree to which the exposure and outcome vary together. Positive numbers indicate that exposure and outcome increase together, negative numbers indicate that the outcome increases as the exposure decreases. Larger numbers indicate stronger correlation); Cornell, Cornell Scale for Depression in Dementia; HAM-D, Hamilton Rating Scale for Depression;MD, mean difference in outcome (Large differences between groups suggests that the exposure might affect the outcome. For continuous exposures, mean difference represents the change in the outcome for one unit increase in the exposure); NPI, Neuropsychiatric Inventory; NR, information not reported (where possible results and 95%CIs were calculated from raw data); PoV, proportion of variance (This is a number between 0–1 indicating the proportion of variance in the outcome explained by the exposure. Higher numbers indicate greater explanatory power of the exposure); SCB, Screen for Caregiver Burden (selection of items); Zung, Short Zung Interviewer Assisted Depression Rating Scale.