AimOur previous work showed that non-pharmacological interventions could effectively reduce the severity of behavioral and psychological symptoms of dementia (BPSD), while the factors influencing the effect of intervention were less explored. Therefore, the main purpose of the present study was to investigate the predictors of the non-pharmacological intervention effect for old veterans with dementia and BPSD. MethodsA total of 141 old veterans with dementia living in two veterans' homes in northern Taiwan were recruited. The participants received an organized non-pharmacological intervention program of physical activity/exercise, music therapy, reality orientation, art therapy, reminiscence therapy and horticultural therapy once every week for 6months. All participants were evaluated by the Barthel Index, Lawton-Brody Instrumental Activities of Daily Living Scale, Mini-Mental State Examination, neuropsychiatric inventory (NPI), and the Cornell Scale for Depression in Dementia before and after the intervention. Logistic regression was used to investigate factors associated with improvement/maintenance of cognition (measured by the Mini-Mental State Examination), and improvement of BPSD (measured by NPI) and its subdomains during the intervention period. ResultsMultivariate logistic regression analysis showed that the improvement/maintenance of cognitive function was independently associated with a lower Mini-Mental State Examination score at baseline (odds ratio [OR] 0.88, 95% CI 0.80-0.97, P=0.008), whereas participants with antipsychotic use were less likely to gain the effect (OR 0.42, 95% CI 0.17-1.04, P=0.061). In addition, the improvement of BPSD was associated with a higher baseline total NPI score (OR 1.33, 95% CI 1.15-1.55, P<0.001), and the result was consistent in different NPI subdomains (psychotic domain: OR 1.96, 95% CI 0.83-4.58, P=0.123; affective domain: OR 1.63, 95% CI 1.25-2.13, P<0.001; behavior domain: OR 2.25, 95% CI 1.53-3.30, P<0.001) and caregiver burden (OR 1.63, 95% CI 1.24-2.14, P<0.001). In addition, a higher Cornell Scale for Depression in Dementia score was correlated with an improvement in the NPI behavior domain (OR 1.48, 95% CI 1.01-2.18, P=0.047), whereas participants with hearing impairment had a lower chance of improvement in the NPI behavior domain (OR 0.11, 95% CI 0.01-1.23, P=0.073) and care burden (OR 0.17, 95% CI 0.03-0.99, P=0.050). ConclusionsOur findings show that non-pharmacological intervention programs have a significant effect on reducing overall NPI score, NPI caregiver burden score and NPI subdomains - psychotic, affective and behavior syndrome - in old veterans with dementia. In addition, participants with lower cognitive performance, more severe BPSD and depressive symptoms at baseline were more likely to gain benefit from the intervention, whereas antipsychotic use and hearing impairment were negative predictors of improvement of cognition and BPSD, respectively. Geriatr Gerontol Int 2017: 17 (Suppl. 1): 28-35.