Table 3.
Subgroup summary data from studies included in each subgroup in the systematic review.
| Mortality | ||
|---|---|---|
| Study | Mortality HRs (95% CI) | Conclusions |
| Blodgett et al., 2016 | 1.04 (1.03–1.06) 0.01 change in FI-Lab score Adjustments: age |
High FI-Lab scores associated with mortality |
| Blodgett et al., 2017 | 1.63, 2.59, 3.62, 6.35 Groupings: 0.1–0.2, 0.2–.03, 0.3–0.4, ˃0.4 Adjustments: age, sex |
High FI-Lab scores associated with mortality |
| Blodgett et al., 2022 | OR: 1.05 (1.04–1.06) 0.01 change in FI-Lab score Adjustments: age, sex |
High FI-Lab scores associated with mortality |
| Ellis et al., 2020 | Unadjusted: 1.51 (1.43–1.60) Adjusted: 1.45 (1.37–1.54) change in FI-Lab score Adjustments: age, sex, clinical frailty score, dementia, delirium, falls, residence at admission |
High FI-Lab scores associated with mortality Higher mortality risk in females |
| Engvig et al., 2022 | Unadjusted: 1.04 (1.02–1.05) Adjusted: 1.03 (1.00–1.05) 0.01 change in FI-Lab score Adjustments: age, ward placement, CCI, CFS, NEWS2 |
High FI-Lab scores associated with mortality in older medical inpatients |
| Gu et al., 2021 | OR: 8.705 (3.646–20.782) Ranked FI-Lab scores |
High FI-Lab scores predict in-hospital mortality in AECOPD patients |
| Guan et al., 2022 | Unadjusted: 1.44 (1.23–1.70) Adjusted: 1.32 (1.11–1.58) 0.1 change in FI-Lab score Adjustments: age, sex, CCI, primary reason for hospital admission |
High FI-Lab scores associated with mortality in geriatric rehabilitation inpatients |
| Hao et al., 2019 | 1.33 (1.09–1.63) Adjustments: age, sex, educational levels |
Higher frailty proportions in mortality group 53.4% rate of 4-year mortality |
| Heikkila et al., 2021 | 1.69–3.75 Groupings: ≤0.08, 0.09–0.42, ≥0.43 Adjustments: age, sex |
High FI-Lab scores predict increase in mortality |
| Howlett et al., 2014 | (1.02–1.04) 0.01 change in FI-Lab score Adjustments: age, sex |
High FI-Lab scores associated with mortality |
| Huang et al., 2022 | Unadjusted: 2.955 (2.172–4.021); 4.997 (3.656–6.831) Adjusted: 2.173 (1.576–2.996); 2.877 (2.026–4.083) Groupings: <0.2 (ref), 0.2–0.35, >0.35 Adjustments: age, sex, smoking history, drinking history, state of consciousness, diabetes, hypertension, CHD, COPD, tumour, stroke history, dementia, respiratory failure, septic shock |
High FI-Lab scores associated with mortality in older community-acquired pneumonia patients |
| Jäger et al., 2019 | 1.066 (1.051–1.081) 0.01 change in FI-Lab score Adjustments: age, sex |
High FI-Lab scores associated with increased mortality rates for 6 months and 1 year after hospital readmission |
| Kim CH et al., 2022 | 1.042 (1.010–1.076) Groupings: 0.32 cut-off in FI-Lab score Adjustments: age, EuroSCORE II, peripheral vascular disease |
High FI-Lab scores predict in-hospital mortality in patients after coronary artery bypass grafting |
| Kim Y et al., 2022 | 1.75 (1.49–2.06); 4.29 (3.41–5.40) Groupings: <0.25 (ref); 0.25–0.4; >0.4 Adjustments: age, sex, number of co-morbidities, operating room duration, cancer stage |
High FI-Lab scores associated with mortality in older surgical patients with cancer |
| Klausen et al., 2017 | 1.94 (1.57–2.40); 2.84 (2.31–3.49); 3.66 (3.00–4.48) Quartiles: 1 (ref); 2; 3; 4 Adjustments: age |
Post-discharge mortality associated with FI-Lab scores |
| Mitnitski et al., 2015 | 1.05 (1.04–1.07) 0.01 change in FI-Lab score Adjustments: sex |
FI-Lab scores strongly associated with mortality |
| Ritt et al., 2017 | 1.071 (1.05–1.093) 0.01 change in FI-Lab score Adjustments: age, sex |
FI-Lab scores predict 6-month and 1-year mortality risk |
| Rockwood et al., 2015 | 1.016 (1.007–1.025) 0.01 change in FI-Lab score Adjustments: age, sex |
High FI-Lab scores associated with mortality |
| Soh et al., 2022 | Unadjusted: 1.351 (1.195–1.528) Adjusted: 1.180 (1.037–1.343) 0.1 change in FI-Lab score Adjustments: age, sex, CCI |
High FI-Lab scores associated with 1-year mortality in geriatric rehabilitation inpatients |
| Sohn et al., 2019 | 1.075 (1.040–1.111) Unadjusted |
High FI-Lab scores associated with early mortality in SAVR patients |
| Stubbings et al., 2021 | – | A quantile FI improves the predictive value of the FI-Lab |
| Wang et al., 2019 | 1.02 (1.01–1.03) 0.01 change in FI-Lab score Adjustments: age, sex |
FI-Lab scores can predict mortality in lung cancer patients |
| Yang et al., 2019 | 1.07 (1.05–1.09) 0.01 change in FI-Lab score Adjustments: age, sex |
FI-Lab scores can predict 1-year mortality |
| Adverse health outcomes | ||
| Study | Risk of adverse outcome | Conclusions |
| Bello et al., 2018 | OR: 1.06 (1.027–1.086) for short-term memory problems OR measured per deficit in FI-Lab |
FI-Lab scores are inversely associated with mental and physical health |
| Blodgett et al., 2016 | OR: 1.02 (1.00–1.04); 1.03 (1.02–1.04); 1.04 (1.02–1.05); 1.03 (1.02–1.05); 1.00 (0.99–1.02); 1.01 (1.00–1.02) for institutionalisation, frequency of doctor visits, high number of medications, poor self-reported health, fractures and falls, respectively 0.01 change in FI-Lab |
High FI-Lab scores are associated with institutionalisation, frequent doctor visits, high number of medications, poor self-reported health and falls |
| Blodgett et al., 2019 | OR: 1.46 (1.39–1.54); 1.41 (1.32–1.50); 1.35 (1.29–1.42) for self-reported health, ADL disability and heath care use 0.10 change in FI-Lab score |
High FI-Lab scores are associated with poor self-reported health, ADL disability and health care use |
| Cheung et al., 2017 | OR: 0.8 (0.3–1.8); 1.6 (0.7–3.7) for adverse discharge destination Groupings: FI-Lab between 0.25–0.4 versus <0.25 and FI-Lab >0.4 versus <0.25 Adjustments: age, total number of co-morbidities and ISS |
Severe frailty based on the FI-Lab was not associated with adverse outcomes |
| Ellis et al., 2020 | Unadjusted OR: 1.61 (1.54–1.69); 1.40 (1.29–1.53); 1.20 (1.12–1.28) Adjusted OR: 1.47 (1.41–1.54); 1.39 (1.27–1.52); 1.18 (1.11–1.26) 0.10 change in FI-Lab score For inpatient days with follow-up as offset, discharge to a higher level of care and readmission, respectively |
FI-Lab scores are associated with adverse outcomes, rates of hospital readmission and discharge location |
| Guan et al., 2022 | Unadjusted OR: 0.98 (0.87–1.11); 0.96 (0.86–1.07) Adjusted OR: 0.98 (0.86–1.12); 1.00 (0.88–1.12) 0.10 change in FI-Lab score Adjustments: age, sex CCI, primary reason for hospital admission For functional decline and institutionalisation, respectively |
FI-Lab scores are associated with functional decline and institutionalisation in geriatric rehabilitation inpatients |
| Heikkila et al., 2021 | – | Laboratory index scores do not significantly predict institutionalisation |
| Huang et al., 2022 | Unadjusted OR-respiratory failure: 3.797 (2.101–6.862); 6.113 (3.358–11.128) Unadjusted OR-septic shock: 4.385 (2.101–9.148); 16.8 (8.272–34.119) Adjusted OR-respiratory failure: 3.326 (1.799–6.15); 5.353 (2.835–10.107) Adjusted OR-septic shock: 3.701 (1.736–7.889); 12.713 (6.112–26.445) Groupings: <0.2 (ref), 0.2–0.35, ≥0.35 Adjustments: age, sex, BMI, smoking history, drinking history, state of consciousness, diabetes, hypertension, CHD, COPD, tumour, stroke history, dementia |
FI-Lab scores are associated with respiratory failure and septic shock in older community-acquired pneumonia patients |
| Justice et al., 2019 | – | FI-Lab scores are associated with pro-inflammatory cytokines |
| Kim CH et al., 2022 | OR: 1.02 (1.002–1.039); 1.06 (1.014–1.039); 1.09 (1.032–1.152) Cut-off: 0.32 FI-Lab score For atrial fibrillation, acute kidney injury and reoperation for bleeding, respectively |
FI-Lab scores associated with atrial fibrillation, acute kidney injury and reoperation for bleeding following coronary artery bypass grafting |
| Kim Y et al., 2022 | OR-readmission within 30 days of surgery: 1.20 (1.04–1.38); 1.49 (1.12–1.98) OR-ICU admission within 30 days of surgery: 1.70 (1.47–1.97); 3.58 (2.77–4.63) Groupings: <0.25 (ref), 0.25–0.4, >0.4 Adjustments: age, sex number of co-morbidity, operating room duration, cancer stage |
FI-Lab scores associated with longer length of stay, readmission after surgery and post-operative ICU admission in older surgical patients with cancer |
| Lim et al., 2022 | OR: 1.51 (0.76–2.99); 2.58 (1.15–5.80) Groupings: <0.25 (ref), 0.25–0.4, >0.4 For readmission within 30 days |
FI-Lab scores associated with longer length of hospital stay, ICU stay and hospital readmission in patients undergoing coronary artery bypass graft surgery |
| Ma, Cai et al., 2018 | Unadjusted OR: 1.33 (1.07–1.64) Adjusted OR: 1.33 (1.08–1.65) 0.10 change in FI-Lab score Adjustments: age groups and gender For QTc interval |
FI-Lab scores are associated with QTc prolongation |
| McMillan et al., 2021 | – | FI-Lab scores inversely associated with fluency, fine motor skills and attention/concentration |
| Naimimohasses et al., 2022 | – | FI-Lab scores increased with severity of non-alcoholic fatty liver disease |
| Nixon et al., 2019 | – | FI-Lab scores are associated with worsening kidney function in CKD patients |
| Sohn et al., 2019 | – | FI-Lab scores are associated with short- and long-term outcomes after SAVR in older patients |
| Wang et al., 2019 | Unadjusted OR: 1.83 (1.25–2.67); 3.19 (1.67–6.09) Adjusted OR: 1.85 (1.26–2.72); 3.19 (1.67–6.12) Groupings: <0.2 versus 0.2–0.35 and < 0.2 versus >0.35 Adjustments: age, sex, occupation, health insurance, BMI, pack-years of cigarettes and drinking history For all adverse reactions |
FI-Lab scores are associated with uncontrolled diseases FI-Lab scores can predict adverse outcomes in cancer patients |
| Sex differences | ||
| Study | Conclusions | |
| Arosio et al., 2022 | No sex differences in FI-Lab scores | |
| Bello et al., 2018 | Higher FI-Lab scores in males | |
| Blodgett et al., 2019 | Higher FI-Lab scores in females aged 20–39, males aged 60+ years | |
| Blodgett et al., 2022 | No sex differences in FI-Lab mortality HRs | |
| Cheung et al., 2017 | No sex differences in FI-Lab scores | |
| Hao et al., 2019 | Higher FI-Lab scores in males | |
| Huang et al., 2022 | No sex difference in FI-Lab scores | |
| King et al., 2017 | Higher FI-Lab scores in males | |
| Lim et al., 2022 | No sex difference in FI-Lab scores | |
| Ma, Liu et al., 2018 | No sex difference in FI-Lab scores | |
| McMillan et al., 2021 | Sex did not confound the association between FI-Lab and cognition | |
| Mitnitski et al., 2015 | Higher FI-Lab scores in females | |
| Naimimohasses et al., 2022 | Higher FI-Lab scores in females | |
Note: CCI, Charlson Co-morbidity Index; CFS, clinical FI; CHD, coronary heart disease; COPD, chronic obstructive pulmonary disease; ICU, intensive care unit; ISS, injury severity score; NEWS2, new early warning score 2; OR, odds ratio; QTc, corrected QT interval.