Effectiveness and implementation of a primary healthcare intervention for multimorbidity and frailty among urban older adults in India: Protocol for the Multi-FrAME cluster randomized trial - Jaya Singh Kshatri; Haimanti Bhattacharya; Siddhartha Goutam; Ashok Kumar Mahakuda; Rasmiranjan Nayak; Kavitha Adukkadukam Kambikanam; Tanveer Rehman; Abhinav Sinha; Mamata Manjari Sahu; Kshanaprava Mohakud; Purna Chandra Das; Sanghamitra Pati (PLoS ONE, 2026)