Development and Pilot Application of a Solution-Focused Intervention for Social Isolation in Elderly Diabetic Foot Patients

Measured by the Lubben Social Network Scale-6 (LSNS-6) , an abbreviated version of the original Lubben Social Network Scale developed by Lubben et al. The LSNS-6 assesses social network status from two dimensions: family network (3 items) and friend network (3 items), totaling 6 items. Each item is rated on a 6-point Likert scale (0 = none, 1 = one, 2 = two, 3 = three to four, 4 = five to eight, 5 = nine or more). Total scores range from 0 to 30. A total score <12 indicates social isolation. Family network score <6 indicates family network isolation, and friend network score <6 indicates friend network isolation. The Chinese version has demonstrated adequate internal consistency with a Cronbach's α of 0.832.

Social support level measured by the Medical Outcomes Study Social Support Survey (MOS-SSS). The MOS-SSS contains 19 items across four dimensions: emotional/informational support (8 items), tangible support (4 items), affectionate support (3 items), and positive social interaction (4 items). Each item is rated on a 5-point Likert scale (1=none of the time, 5=all of the time). Total scores are transformed to a 0-100 scale, with higher scores indicating better social support. The Chinese version has demonstrated good reliability and validity, with a Cronbach's α of 0.91.

Social participation level measured by the Social Participation Scale. This scale assesses the frequency and diversity of social activities across multiple domains, including family interactions, community activities, and social gatherings. Each item is rated on a 5-point Likert scale (1=never, 5=very often). Higher total scores indicate a higher level of social participation. The scale has been validated in older adult populations with chronic diseases, demonstrating satisfactory psychometric properties with a Cronbach's α of 0.85.

Depressive symptoms measured by the Patient Health Questionnaire-9 (PHQ-9). The PHQ-9 consists of 9 items corresponding to the DSM-IV diagnostic criteria for major depressive disorder. Each item is rated on a 4-point Likert scale (0=not at all, 1=several days, 2=more than half the days, 3=nearly every day) based on symptom frequency over the past two weeks. Total scores range from 0 to 27, with higher scores indicating more severe depressive symptoms (0-5 minimal, 6-10 mild, 11-15 moderate, 16-20 moderately severe, 21-27 severe). Cronbach's α=0.89.

Glycemic control measured by fasting blood glucose (FBG) in millimoles per liter (mmol/L). Venous blood samples are collected after an 8-hour overnight fast and analyzed using the standardized glucose oxidase method. Lower FBG values indicate better glycemic control. According to the Chinese Diabetes Society guidelines, normal FBG is 3.9-6.1 mmol/L. This objective biomarker provides a reliable assessment of short-term glycemic status.

Diabetic foot self-care behaviors measured by the Diabetic Foot Self-Care Behavior Scale. This scale evaluates patients' adherence to recommended foot care practices, including daily foot inspection, proper washing and drying, moisturizing, nail care, appropriate footwear selection, and avoiding barefoot walking. Items are rated on a 5-point Likert scale (1=never, 5=always). Higher total scores indicate better adherence to diabetic foot self-care behaviors. The scale has shown good reliability with a Cronbach's α of 0.88.