The mediating effect of pain on the association between multimorbidity and disability and impaired physical performance among community-dwelling older adults in southern China.

Aim: To investigate the association between multimorbidity and disability and impaired physical performance, and to further evaluate the mediating effect of physical pain in this association.

Methods: 1321 community-dwelling older adults, who were over 60 years old in southern China, were regarded as participants in this cross-sectional study. Subjects completed a multi-instrument questionnaire including essential characteristics and physical function assessments. Physical function was assessed by activities of daily living (ADL), instrumental activities of daily living (IADL), index of mobility scale (NAGI), index of basic physical activities scale (RB), and short physical performance battery (SPPB). Multimorbidity was defined as the simultaneous presence of two or more chronic conditions. Multivariable regression and mediation analyses were conducted and gender differences were explored.

Results: The prevalence of multimorbidity was 44.6% in our study. In gender stratification analysis, multimorbidity was significantly associated with ADL disability (OR = 2.16), IADL disability (OR = 1.97), NAGI disability (OR = 2.84), RB disability (OR = 2.65) and lower SPPB score (β = - 0.83) in women. The rate of pain increased with the number of chronic diseases and the multimorbidity patients with higher pain prevalence. Moreover, the presence of pain was also significantly associated with disability and impaired physical performance. Mediation analysis illustrated that pain was accounted for 16.5% to 22.1% of the adverse effects of multimorbidity on disability and impaired physical performance in women.

Conclusions: Multimorbidity was significantly associated with disability and impaired physical performance, and pain might be a mediating factor for adverse effects of multimorbidity on disability and impaired physical performance in women.