Effect estimates for outcomes and certainty of evidence, for all interventions combined and by intervention category
| Category; outcome*† | No. of studies | No. of participants | SMD‡ (95% CI)§ | GRADE rating |
|---|---|---|---|---|
| Nutrition interventions | ||||
| Physical function | 7 | 694 | 0.16 (0.02 to 0.29) | Moderate; downgraded for risk of bias |
| Mobility | 7 | 694 | 0.15 (0.001 to 0.30) | Moderate; downgraded for risk of bias |
| Health | 4 | 284 | −0.18 (−0.51 to 0.16) | Low; downgraded for risk of bias and imprecision |
| Frailty | 3 | 255 | −0.22 (−0.44 to −0.01) | Moderate; downgraded for risk of bias |
| Diet quality | 5 | 383 | 0.10 (−0.47 to 0.67) | Very low; downgraded for risk of bias, inconsistency and imprecision |
| Quality of life | 1 | 243 | −0.12 (−1.39 to 1.15) | Moderate; downgraded for imprecision |
| Protein supplementation interventions | ||||
| Physical function | 5 | 344 | 0.16 (0.01 to 0.31) | Moderate; downgraded for risk of bias |
| Mobility | 5 | 344 | 0.20 (0.02 to 0.39) | Moderate; downgraded for risk of bias |
| Health | 3 | 177 | −0.12 (−0.58 to 0.34) | Low; downgraded for risk of bias and imprecision |
| Frailty | 2 | 148 | −0.18 (−0.45 to 0.09) | Low; downgraded for risk of bias and imprecision |
| Diet quality | 4 | 297 | −0.01 (−0.69 to 0.67) | Very low; downgraded for risk of bias, inconsistency and imprecision |
| Combined-approach (nutrition and physical activity) interventions | ||||
| Physical function | 6 | 514 | 0.19 (0.06 to 0.32) | Moderate; downgraded for risk of bias |
| Mobility | 6 | 514 | 0.25 (0.02 to 0.48) | Moderate; downgraded for risk of bias |
| Health | 3 | 310 | −0.05 (−0.42 to 0.33) | Low; downgraded for risk of bias and imprecision |
| Frailty | 2 | 213 | −0.41 (−0.68 to −0.14) | Moderate; downgraded for risk of bias |
| 3 | 359 | RR 0.72 (0.52 to 1.00)¶ | Moderate; downgraded for risk of bias | |
| Diet quality | 2 | 141 | 0.53 (−0.98 to 2.04) | Very low; downgraded for risk of bias, inconsistency and imprecision |
| Quality of life | 3 | 267 | 0.31 (−0.05 to 0.67) | Low; downgraded for risk of bias and imprecision |
Note: CI = confidence interval, RR = risk ratio, SMD = standardized mean difference.
↵* Physical function: activities of daily living, muscle strength (handgrip and nonhandgrip) and appendicular lean mass; mobility: gait speed, Timed Up and Go test, Sit-to-Stand test, balance test and Short Physical Performance Battery; health: body weight and body mass index; diet quality: energy intake in calories.
↵† For all interventions, there were no data for death, use of health care services, or caregiver and social support. For protein supplementation interventions, there were no data for quality of life.
↵‡ Except where noted otherwise.
↵§ Large: ~0.8; medium: ~0.5; small: ~0.2.
↵¶ Dichotomous outcome.