Characteristics of the included studies
| Study, year; country | No. of participants (F/M, %) | Age, mean ± SD,* yr | Assessment tool or measure | Design; duration† | Intervention | Control | Outcomes |
|---|---|---|---|---|---|---|---|
| Nutrition interventions | |||||||
| Wu et al., (24) 2018; Taiwan | 40 (56/44‡) | O: 74.0 I: 73.5 ± 2.4, 75.0 ± 2.4, 72.8 ± 1.6 C: 75.9 ± 1.7 | Fried’s frailty phenotype§ | RCT; 3 mo | Oral nutrition supplements, fortified/enhanced foods, nutrition/dietitian counselling | General nutrition information | Health (and death), physical function (and quality of life), mobility, diet quality |
| Niccoli et al., (25) 2017; Canada | 53 (68/32‡) | O: 81.3 ± 1.0 I: 81.77 ± 1.68 C: 80.33 ± 1.57 | Fried’s frailty phenotype§ | RCT; ~ 3–4 wk | Fortified/enhanced foods | Control food without supplements | Physical function (and quality of life), frailty, mobility |
| Park et al., (26) 2018; Korea | 120 (65/35) | I: 77.30 ± 3.67, 76.80 ± 3.70 C: 76.83 ± 3.86 | Cardiovascular Health Study criteria§ | RCT; 12 wk | Fortified/enhanced foods | Placebo powder | Physical function (and quality of life), frailty, mobility, diet quality |
| Ng et al., (8), (36), (37) 2015; Singapore | 246 (61/39) | O: 70.0 ± 4.7 I: 69.7 ± 4.23 C: 70.1 ± 5.02 | Cardiovascular Health Study criteria§ | RCT; 6 mo | Oral nutrition supplements, fortified/enhanced foods | Placebo supplement | Health (and death), physical function (and quality of life), use of health care services, frailty, mobility |
| Kim et al., (27) 2013; South Korea | 87 (79/21) | I: 78.9 ± 5.5 C: 78.4 ± 6.0 | Slow gait speed, MNA | RCT; 12 wk | Oral nutrition supplements, fortified/enhanced foods | No contact or care | Health (and death), physical function (and quality of life), frailty, mobility, diet quality |
| Tieland et al., (28), (38) 2012; the Netherlands | 65 (55/45) | O: 83.1 ± 5.1 I: 78.0 ± 1 C: 81.0 ± 1 | Fried’s frailty phenotype | RCT; 24 wk | Fortified/enhanced foods | Placebo supplement | Health (and death), physical function (and quality of life), mobility, diet quality |
| Latham et al., (22) 2003; New Zealand | 243 (53/47) | O: 79.1 ± 6.9 I: 79.0 (95% CI 77 to 80) C: 80.0 (95% CI 78 to 81) | Clinical measures of frailty§ | RCT; 3 mo | Oral nutrition supplements | Placebo supplement | Physical function (and quality of life), mobility |
| de Jong et al., (23), (39), (40) 2000;¶ the Netherlands | 217 (70/30) | O: 79.0 I: 79.6 ± 4.8 C: 79.3 ± 6.6 | Required health care service (e.g., home care, meal delivery) | RCT 17 wk | Fortified/enhanced foods | Control food without supplements | Physical function (and quality of life), mobility, diet quality |
| Combined-approach interventions | |||||||
| Kang et al., (29) 2019; China | 115 (62/38) | O: 77.3 I: 76.79 ± 7.11, 78.04 ± 6.82 | Fried’s frailty phenotype§ | CCT; 12 wk | Fortified/enhanced foods, muscle strengthening | Information about diet to maintain current weight, usual daily exercise program | Health (and death), physical function (and quality of life), mobility |
| Serra-Prat et al., (30) 2017; Spain | 172 (56/44) | O: 78.3 I: 77.9 ± 5.0 C: 78.8 ± 4.9 | Fried’s frailty phenotype | RCT; 12 mo | Nutrition/dietitian counselling, mixed physical activity (muscle strengthening/aerobic/exercises) | Usual care | Frailty, health (and death), physical function (and quality of life), mobility |
| Luger et al., (31), (41)– (44) 2016; Austria | 80 (84/16) | O: 82.8 ± 8.0 I: 83.0 ± 8.1 C: 82.5 ± 8.0 | SHARE-FI§ | RCT; 12 wk | Nutrition/dietitian counselling, muscle strengthening | Visited 2×/wk by “buddies” | Frailty, physical function (and quality of life), mobility |
| Kwon et al., (32) 2015; Japan | 89 (100/0) | O: 76.8 I: 76.5 ± 3.8, 77.0 ± 4.2 C: 76.9 ± 3.9 | Fried’s frailty phenotype§ | RCT; 3 mo | Nutrition/dietitian counselling, muscle strengthening | General health education session 1×/mo | Frailty, physical function (and quality of life), mobility |
| Tieland et al., (33), (45), (46) 2012; the Netherlands | 62 (66/34) | I: 78 ± 9 C: 79 ± 6 | Fried’s frailty phenotype | RCT; 24 wk | Fortified/enhanced foods, muscle strengthening | Exercise training 2×/wk, placebo supplement 2×/d | Health (and death), physical function (and quality of life), mobility, diet quality |
| Yamada et al., (35) 2012; Japan | 77 (51/49‡) | I: 74.4 ± 7.3 C: 75.6 ± 6.0 | Frailty status as certified by long-term care insurance service | CCT; 3 mo | Oral nutrition supplements, fortified/enhanced foods, muscle strengthening | Both groups received exercise training | Physical outcomes (and quality of life), mobility |
| de Jong et al., (23), (39), (40) 2000;** the Netherlands | 217 (70/30) | O: 79.0 I: 79.2 ± 6.1 C: 79.3 ± 6.6 | Required health care service (e.g., home care, meal delivery) | RCT; 17 wk | Fortified/enhanced foods, mixed physical activity (muscle strengthening/aerobic/exercises) | Control food, social program once every 2 wk for 90 min | Physical function (and quality of life), mobility, diet quality |
| Nykänen et al., (34) 2012; Finland | 159 (79/21) | O: 83.1 ± 5.1 I: 83.2 ± 5.2 C: 82.9 ± 5.0 | Cardiovascular Health Study criteria§ | CCT; 1 yr | Nutrition/dietitian counselling, mixed physical activity (muscle strengthening/aerobic/exercises) | Usual care | Frailty, diet quality |
Note: C = control, CCT = clinical controlled trial, CI = confidence interval, F = female, I = intervention, M = male, MNA = Mini Nutritional Assessment, O = overall, RCT = randomized controlled trial, SD = standard deviation, SHARE-FI = Frailty Instrument of the Survey of Health, Ageing and Retirement in Europe.
↵* Except where noted otherwise.
↵† Not including follow-up, if applicable.
↵‡ Values based on reported baseline, which may not equal the number randomly allocated but, rather, the number who completed the intervention.
↵§ Authors indicated that the assessment tool was modified from standard protocol.
↵¶ Describes nutrition-only intervention arm compared to control, as this study was also included in the combined-approach analysis.
↵** Describes combined-approach intervention arm compared to control, as this study was also included in the nutrition analysis.