Table 1.
Basic characteristics of the included studies.
| Study (year) | Study design | Country | Setting | Sample size | Age (years) | Female (%) | Identification for hypertension | Frailty measurements | Frailty (%) | Follow-up period (years) | Outcome | Effect measure | Adjustment factors | NOS |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Bromfield (2017) [28] | Longitudinal | United States | Community | 5236 | ≥65 | 53.7 | Taking antihypertensive drugs | Indicators of frailty# | 5.9 | 6.4 | Injurious falls | HR | Age, sex, race, region of residence, education, income, cigarette smoking, statin use, osteoporosis use, benzodiazepines use, albumin to creatinine ratio, diabetes, history of heart disease, history of stroke, SBP, DBP, number of antihypertensive medication classes taken | 8 |
| Pajewski (2016) [29] | Longitudinal | United States | Hospital | 9306 | ≥50 | 35.5 | SBP within the range of 130–180, 130–170, 130–160, or 130–150 mmHg while being on no more than 0/1, 2, 3, or 4 antihypertensive drugs, respectively | 36-item frailty index | 27.6 | 2.6 | Injurious falls All-cause hospitalizations |
HR | Age, sex, race/ethnicity, education, alcohol consumption, and treatment arm | 7 |
| Lina (2018) [30] | Longitudinal | China | Community | 1111 | ≥60 | 53.3 | SBP ≥ 140 mmHg or DBP ≥ 90 mmHg or self-reported hypertension or receiving antihypertensive drugs | CGA | 19.6 | 8.0 | All-cause mortality | HR | Age, sex | 7 |
| Vaes (2017) [31] | Longitudinal | Belgium | Hospital | 301∗ | ≥80 | NA | SBP ≥ 140 mmHg | Groningen Frailty Indicator; frailty phenotype; frailty index | 30.0 | 5.1 | All-cause mortality Cardiovascular mortality |
HR | NA | 8 |
| Ying-Yi (2018) [32] | Longitudinal | China | Hospital | 348 | ≥65 | 10.0 | SBP ≥ 140 mmHg or DBP ≥ 90 mmHg or receiving antihypertensive drugs | Frailty phenotype | 38.1 | 0.4 | All-cause hospitalizations Hypertensive end-organ damage (apresence of proteinuria) |
HR, OR | Age, malnutrition, cognitive decline, polypharmacy, complication, orthostatic hypotension, proteinuria | 7 |
| Misis (2015) [33] | Longitudinal | Spain | Community | 541∗ | ≥65 | NA | SBP ≥ 140 mmHg | Walking speed < 0.8 m/s | 39.0 | 5.3 | All-cause mortality | HR | NA | 8 |
| Tabara (2016) [34] | Cross-sectional | Japan | Community | 560 | ≥45 | NA | SBP ≥ 140 mmHg or DBP ≥ 90 mmHg or taking antihypertensive drugs | Simple frailty score# | 12.1 | NA | Hypertensive end-organ damage (apresence of proteinuria, bWMH, or chigh BNP) | OR | Age, sex | 7 |
#The most severe group was frailty, whose data were compared with the nonfrailty group. ∗Subgroup participant samples were obtained by contacting the corresponding author. aProteinuria was defined as urinary protein/creatinine ratio ≥ 0.1 g/g creatinine or routine urine test showed positive urine protein. bThe presence of WMHs was defined as periventricular hyperintensity (PVH) grade ≥ 2 and/or deep subcortical white matter hyperintensity (DSWMH) grade ≥ 3 (PVH was classified into five grades: grade 0, absent or only a “rim”; grade 1, limited lesion-like “caps”; grade 2, irregular “halo”; grade 3, irregular margins and extension into the deep white matter; and grade 4, extension into the deep white matter and subcortical portion; DSWMH was also classified into five grades: grade 0, absent; grade 1, ≤3 mm small foci and regular margins; grade 2, ≥3 mm large foci; grade 3, diffusely confluent; grade 4, extensive changes in the white matter). cHigh BNP was defined as BNP ≥ 100 pg/ml. CGA: comprehensive geriatric assessment; SBP: systolic blood pressure; DBP: diastolic blood pressure; HR: hazard ratio; OR: odds ratio; NA: not applicable; BNP: B-type natriuretic peptide; WMH: white matter hyperintensity.