AUTHOR=Ho Vanda , Chan Yiong Huak , Merchant Reshma Aziz 

TITLE=Patterns of improvement in functional ability and predictors of responders to dual-task exercise: A latent class analysis

JOURNAL=Frontiers in Public Health

VOLUME=Volume 10 - 2022

YEAR=2023

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2022.1069970

DOI=10.3389/fpubh.2022.1069970

ISSN=2296-2565

ABSTRACT=Background
Exercise is the pillar for healthy aging. ‘Non-responders’ may be due to a mismatch in exercise prescription. Latent cluster analysis (LCA) profile can be useful to uncover subpopulations sharing similar profiles or outcomes. We aim to use LCA to develop a response prediction model for older adults who would benefit from The Healthy Aging Promotion Program for You, a community embedded dual-task exercise program.

Methods
197 participants completed the 3 months follow-up and complete data was available for 136 community-dwelling older adults. Inclusion criteria were age ≥60years, pre-frail or frail and ambulant, mild cognitive impairment and able to provide consent. Data collected include demographics, education, falls, physical function (Katz ADL scale, Lawton’s IADL scale), physical activity (rapid assessment of physical activity), cognition (Montreal Cognitive Assessment;MoCA), frailty(FRAIL scale), perceived health, pain, anxiety/depression, fear of falling and social isolation(Lubben Social Network Scale). Body mass index (BMI), handgrip strength and short physical performance battery (SPPB) were measured. Those who improved in frailty, anxiety/depression, pain, Lubben, MoCA, SPPB, fear-of-falling, physical activity, falls and HGS were classified as responders.

Results
Mean age was 74.7 years, BMI 23.5 kg/m2, 23.5% male, 96.3% of Chinese ethnicity, 61% pre-frail, education level 4.3 years, and MoCA score of 23.3±4.8. Two clusters were identified: non-responders (61.8%) and responders (38.2%). Responders had significant improvement in cognition (44.2% vs 0,p<0.001) and SPPB (gait:28.8% vs 0,p<0.001; balance:42.3% vs 15.5%,p=0.001; chair-stand:65.4% vs 4.8%,p<0.001). Responders were significantly older (76.9 vs 73.3 years,p=0.005), had higher BMI (24.8 kg/m2 vs 22.8 kg/m2,p=0.007), lower education (3.4 vs 4.9 years,p=0.021), lower MoCA scores (21.8 vs 24.3,p=0.002), and lower SPPB scores (8.7 vs 10.6,p<0.001).

The predictive variables for responder cluster were age ≥75years, BMI≥23kg/m2, robust, no anxiety, pain, fear of falling, MoCA≤22, Lubben≤12, SPPB score: chair-stand≤2, balance≤2, gait>2, handgrip strength <20kg, no falls and RAPA>3. With an optimal cut-off of ≥12, this prediction model had sensitivity 76.9%, specificity 70.2%, positive predictive value 61.5% and negative predictive value 83.1%. 

Conclusion
Response to dual-task exercise was influenced by age, SPPB, BMI and cognition. Prospective longitudinal studies are needed to validate this LCA model and guide in development of public health strategies.