Background
Methods
Design and setting of the study
Healthy ageing index
- difficulty in: household responsibilities, walking a kilometre, washing whole body, getting dressed, carrying out work and everyday activities (World Health Organization Disability Assessment Schedule 2.0, WHO-DAS II)
- difficulty in: making decisions, using the toilet, handling money, finding right word, completing chores; change in daily activities and forgets where he/she is (Community Screening Interview for Dementia-Informant Scale, CSI’D’-RELSCORE)
- sleep trouble or recent change in pattern; feeling of not coping properly with everyday routine; getting worn out or exhausted during daytime or evening (Geriatric Mental State Interview, GMS)
- delayed recall; long memory test; immediate recall; verbal fluency; time orientation; praxis-fold a piece of paper; story recall difficulty (Neurological Examination and Community Screening Interview for Dementia, CSI’D’)
- word list learning; time in seconds taken to walk 10 m; hearing problem; sight problem. All interview manuals and questionnaires are available, upon request, on the official site of the study: https://www.alz.co.uk/1066/population_based_study_prevalence.php.
Mortality outcome
Incident dependence outcome
Covariates
Statistical analyses
- Censored: survived and participated in the follow-up survey with no need for care.
- Incident dependent: identified as dependent from the follow-up interview or, if dead, from the informant deceased interview.
- Having competing event: dead but with no incident dependence as identified by the informant deceased interview.
Results
Sample study characteristics
Mortality Cohort | Cuba | Dominican Republic | Mexico | Peru | Puerto Rico | Venezuela | Total |
---|---|---|---|---|---|---|---|
Baseline sample (alive at baseline) | 2813 | 2011 | 2003 | 1933 | 2009 | 1965 | 12,734 |
Vital status determined (% of baseline) | 2635 (93.7%) | 1706 (84.8%) | 1844 (92.1%) | 1752 (90.6%) | 1563 (77.8%) | 1697 (86.4%) | 11,197 (87.9%) |
Interviewed (% of baseline sample) | 2007 (71.3%) | 1197 (59.5%) | 1459 (72.8%) | 1311 (67.8%) | 1265 (63.0%) | 1257 (64.0%) | 8496 (66.7%) |
Deaths (% of those with vital status determined) | 608 (23.1%) | 467 (27.4%) | 209 (11.3%) | 152 (8.7%) | 298 (19.1%) | 200 (11.8%) | 1934 (17.3%) |
Person years of follow-up | 10,844.6 | 7448.6 | 5366.7 | 5356.8 | 6474.3 | 7031.0 | 42,521.9 |
Mortality rate per 1000 person-years | 56.1 | 62.7 | 38.9 | 28.4 | 46.0 | 28.4 | 45.5 |
Median years of follow-up (25th and 75th centile) | 4.2 (3.5–5.0) | 5.0 (3.6–5.1) | 3.0 (2.9–3.1) | 3.0 (2.5–3.7) | 4.3 (3.7–4.7) | (4.0–4.8) | 3.9 (3.0–4.8) |
Mean age at baseline (SD) | 75.2 (7.1) | 75.3 (7.5) | 74.3 (6.7) | 74.8 (7.4) | 76.3 (7.4) | 72.5 (6.9) | 74.8 (7.2) |
Female Sex (%) | 1836 (65.3%) | 1325 (65.9%) | 1268 (63.3%) | 1183 (61.2%) | 1347 (67.0%) | 1252 (63.7%) | 8211 (64.5%) |
None did not complete primary education (%) | 692 (24.6%) | 1414 (70.3%) | 1418 (70.8%) | 352 (18.2%) | 461 (22.9%) | 601 (30.6%) | 4938 (38.8%) |
Median number of assets (25th–75th centile) | 6.0 (5.0–6.0) | 5.0 (4.0–6.0) | 6.0 (4.0–6.0) | 6.0 (6.0–6.0) | 7.0 (6.0–7.0) | 6.0 (6.0–7.0) | 6.0 (5.0–7.0) |
No limiting physical impairment (%) | 1207 (42.9%) | 599 (29.8%) | 835 (41.7%) | 887 (45.9%) | 708 (35.2%) | 748 (38.1%) | 4984 (39.1%) |
No stroke (%) | 2605 (92.6%) | 1842 (91.6%) | 1871 (93.4%) | 1825 (94.4%) | 1841 (91.6%) | 1846 (93.9%) | 11,830 (92.9%) |
No ICD10 depressive episode (%) | 2671 (95.0%) | 1733 (86.2%) | 1911 (95.4%) | 1830 (94.7%) | 1962 (97.7%) | 1858 (94.6%) | 11,965 (94.0%) |
No dementia (%) | 2517 (89.5%) | 1769 (88.0%) | 1823 (91.0%) | 1767 (91.4%) | 1765 (87.9%) | 1820 (92.6%) | 11,461 (90.0%) |
Q1 of healthy ageing (highest level) | 660 (23.5%) | 199 (9.9%) | 274 (13.7%) | 482 (24.9%) | 347 (17.3%) | 576 (29.3%) | 2538 (19.9%) |
Self-rated health: very good | 287 (10.2%) | 272 (13.5%) | 392 (19.6%) | 409 (21.2%) | 157 (7.8%) | 288 (14.7%) | 1805 (14.2%) |
Dependence Cohort | Cuba | Dominican Republic | Mexico | Peru | Puerto Rico | Venezuela | Total |
---|---|---|---|---|---|---|---|
Baseline sample (no needs for care at baseline) | 2225 | 1770 | 1807 | 1770 | 1714 | 1754 | 11,040 |
Follow-up tracing | |||||||
Interviewed (% of baseline sample) | 1679 (75.5%) | 1103 (62.3%) | 1352 (74.8%) | 1234 (69.7%) | 1174 (68.5%) | 1154 (65.8%) | 7696 (69.7%) |
Deceased (% of baseline sample) | 386 (17.3%) | 345 (19.5%) | 159 (8.8%) | 97 (5.5%) | 176 (10.3%) | 139 (7.9%) | 1302 (11.8%) |
Refused (% of baseline sample) | 12 (0.5%) | 39 (2.2%) | 164 (9.1%) | 273 (15.4%) | 5 (0.3%) | 217 (12.4%) | 710 (6.4%) |
Lost (% of baseline sample) | 148 (6.7%) | 283 (16.0%) | 132 (7.3%) | 166 (9.4%) | 359 (20.9%) | 244 (13.9%) | 1332 (12.1%) |
Participants contribute to competing risk analysis (% of baseline sample) | 2065 (92.8%) | 1448 (81.8%) | 1511 (83.6%) | 1331 (75.2%) | 1350 (78.8%) | 1293 (73.7%) | 8998 (81.5%) |
Incidence dependencea | 271 (13.1%) | 376 (26.0%) | 209 (13.8%) | 156 (11.7%) | 276 (20.4%) | 238 (18.4%) | 1526 (17.0%) |
Competing risk (dependence free death) | 78 (3.8%) | 202 (14.0%) | 66 (4.4%) | 55 (4.1%) | 116 (8.6%) | 80 (6.2%) | 597 (6.6%) |
Person-years at risk for competing risk analysis (divided by two for incident dependence) | 8106.6 | 5800.9 | 4132.9 | 3928.2 | 5196 | 4944.1 | 32,108.7 |
Incidence rate per 1000 person-years | 33.4 | 64.8 | 50.6 | 39.7 | 53.1 | 48.1 | 47.5 |
Median person-years at risk for competing risk analysis (25th and 75th centile) | 4.1 (3.2–4.9) | 4.9 (2.5–5.1) | 3.0 (2.8–3.1) | 3.0 (2.4–3.7) | 4.2 (2.9–4.6) | 4.2 (3.5–4.6) | 3.7 (2.7–4.6) |
For those contributing in competing risk analysis | |||||||
Mean age at baseline (SD) | 74.4 (6.6) | 74.5 (7.0) | 73.9 (6.4) | 74.3 (7.1) | 75.2 (6.5) | 71.5 (6.1) | 74.0 (6.7) |
Female Sex (%) | 1296 (62.8%) | 949 (65.5%) | 957 (63.3%) | 802 (60.3%) | 903 (66.9%) | 808 (62.5%) | 5715 (63.5%) |
None or did not complete primary education (%) | 479 (23.2%) | 1028 (71.0%) | 1051 (69.6%) | 256 (19.2%) | 265 (19.6%) | 363 (28.1%) | 3442 (38.3%) |
Median number of assets (25th–75th centile) | 6.0 (5.0–6.0) | 5.0 (4.0–6.0) | 6.0 (4.0–6.0) | 6.0 (5.0–6.0) | 7.0 (7.0–7.0) | 6.0 (6.0–7.0) | 6.0 (5.0–7.0) |
No limiting physical impairment (%) | 918 (44.5%) | 448 (30.9%) | 654 (43.3%) | 614 (46.1%) | 517 (38.3%) | 520 (40.2%) | 3671 (40.8%) |
No stroke (%) | 1945 (94.2%) | 1347 (93.0%) | 1432 (94.8%) | 1279 (96.1%) | 1271 (94.1%) | 1231 (95.2%) | 8505 (94.5%) |
No ICD10 depressive episode (%) | 1993 (96.5%) | 1269 (87.6%) | 1456 (96.4%) | 1273 (95.6%) | 1325 (98.1%) | 1241 (96.0%) | 8557 (95.1%) |
No dementia (%) | 1969 (95.4%) | 1323 (91.4%) | 1426 (94.4%) | 1270 (95.4%) | 1299 (96.2%) | 1259 (97.4%) | 8546 (95.0%) |
Q1 of healthy ageing (highest level) | 477 (23.1%) | 148 (10.2%) | 196 (13.0%) | 324 (24.3%) | 242 (17.9%) | 409 (31.6%) | 1796 (20.0%) |
Self-rated health: very good | 236 (11.4%) | 207 (14.3%) | 299 (19.8%) | 284 (21.3%) | 116 (8.6%) | 215 (16.6%) | 1357 (15.1%) |
Associations between healthy ageing and mortality
Hazard Ratios (HR) and 95%CI | |||||
---|---|---|---|---|---|
Healthy Ageing | Q1 quintile | Q2 quintile | Q3 quintile | Q4 quintile | Q5 quintile |
Model 1 | 6.89 (5.81–8.17) | 2.61 (2.16–3.14) | 1.89 (1.55–2.29) | 1.26 (1.02–1.56) | reference |
I2 = 53.4%, p = 0.057 | I2 = 0.0%, p = 0.431 | I2 = 0.0%, p = 0.615 | I2 = 29.8%, p = 0.212 | ||
Model 2 | 4.23 (3.48–5.13) | 2.03 (1.67–2.48) | 1.60 (1.31–1.95) | 1.16 (0.94–1.44) | reference |
I2 = 17.1%, p = 0.304 | I2 = 0.0%, p = 0.585 | I2 = 0.0%, p = 0.714 | I2 = 22.6%, p = 0.264 | ||
Model 3 | 3.25 (2.63–4.02) | 1.88 (1.53–2.30) | 1.56 (1.27–1.91) | 1.15 (0.93–1.43) | reference |
I2 = 28.7%, p = 0.220 | I2 = 0.0%, p = 0.524 | I2 = 0.0%, p = 0.726 | I2 = 26.0%, p = 0.239 | ||
Self-rated health | very low | low | moderate | good | very good |
Model 1 | 4.65 (3.53–6.13) | 2.36 (1.94–2.88) | 1.33 (1.14–1.55) | 1.06 (0.91–1.25) | reference |
I2 = 68.0%, p = 0.008 | I2 = 73.5%, p = 0.002 | I2 = 30.4%, p = 0.207 | I2 = 57.0%, p = 0.040 | ||
Model 2 | 4.12 (3.07–5.54) | 2.09 (1.71–2.57) | 1.24 (1.06–1.45) | 0.99 (0.85–1.17) | reference |
I2 = 64.6%, p = 0.015 | I2 = 74.5%, p = 0.001 | I2 = 61.7%, p = 0.023 | I2 = 67.6%, p = 0.009 | ||
Model 3 | 2.78 (2.05–3.76) | 1.68 (1.35–2.09) | 1.16 (0.98–1.36) | 0.98 (0.83–1.15) | reference |
I2 = 55.0%, p = 0.049 | I2 = 73.9%, p = 0.002 | I2 = 51.3%, p = 0.068 | I2 = 69.9%, p = 0.005 |
Associations between healthy ageing and incident dependence
Incident dependence sub-HR (95% CI) | |||||
---|---|---|---|---|---|
Healthy Ageing | Q1 quintile | Q2 quintile | Q3 quintile | Q4 quintile | Q5 quintile |
Model 1 | 10.61 (8.38–13.43) | 4.38 (3.42–5.61) | 2.85 (2.20–3.68) | 1.86 (1.42–2.45) | reference |
I2 = 0.0%, p = 0.468 | I2 = 0.0%, p = 0.696 | I2 = 0.0%, p = 0.663 | 0.0%, p = 0.670 | ||
Model 2 | 7.76 (6.04–9.97) | 3.63 (2.80–4.70) | 2.52 (1.94–3.27) | 1.72 (1.30–2.27) | reference |
I2 = 0.0%, p = 0.949 | I2 = 0.0%, p = 0.915 | I2 = 0.0%, p = 0.904 | I2 = 0.0%, p = 0.830 | ||
Model 3 | 5.21 (4.02–6.75) | 3.53 (2.71–4.59) | 2.60 (2.00–3.35) | 1.74 (1.32–2.29) | reference |
I2 = 0.0%, p = 0.735 | I2 = 0.0%, p = 0.819 | I2 = 0.0%, p = 0.889 | I2 = 0.0%, p = 0.799 | ||
Self-rated health | very low | low | moderate | good | very good |
Model 1 | 2.18 (1.30–3.64) | 2.33 (1.84–2.94) | 1.54 (1.30–1.83) | 1.14 (0.96–1.35) | reference |
I2 = 47.4%, p = 0.107 | I2 = 65.1%, p = 0.014 | I2 = 54.6%, p = 0.051 | I2 = 24.1%, p = 0.253 | ||
Model 2 | 1.77 (0.99–3.18) | 2.03 (1.60–2.57) | 1.37 (1.15–1.62) | 1.02 (0.85–1.22) | reference |
I2 = 1.3%, p = 0.399 | I2 = 54.6%, p = 0.051 | I2 = 59.2%, p = 0.031 | I2 = 39.6%, p = 0.141 | ||
Model 3 | 1.51 (0.77–2.94) | 1.70 (1.29–2.24) | 1.29 (1.07–1.55) | 1.01 (0.84–1.21) | reference |
I2 = 0.0%, p = 0.529 | I2 = 0.0%, p = 0.616 | I2 = 19.7%, p = 0.285 | I2 = 4.1%, p = 0.390 |
Population attributable fraction
Population attributable fraction (95% CI) | ||
---|---|---|
Healthy ageing | Self-rated health | |
Mortality | ||
Cuba | 44.0% (34.7–52.0%) | 19.2% (11.3–26.5%) |
Dominican Republic | 33.6% (17.2–46.8%) | 6.1% (−4.5–15.6%) |
Mexico | 32.4% (4.8–52.0%) | 18.5% (4.6–30.4%) |
Peru | 52.5% (31.2–67.3%) | 17.0% (−0.3–31.3%) |
Puerto Rico | 51.0% (34.5–63.3%) | 19.8% (7.7–30.3%) |
Venezuela | 49.1% (33.7–60.9%) | 30.0% (16.3–41.4%) |
Weighted Mean | 43.6% | 18.4% |
Incident dependence | ||
Cuba | 57.7% (44.5–67.7%) | 16.8% (5.2–27.0%) |
Dominican Republic | 58.0% (43.8–68.6%) | 7.4% (−3.6–17.3%) |
Mexico | 61.4% (40.4–75.0%) | 18.3% (4.5–30.1%) |
Peru | 64.8% (44.6–77.6%) | 24.6% (8.2–38.1%) |
Puerto Rico | 58.6% (45.8–68.4%) | 6.7% (−5.2–17.3%) |
Venezuela | 51.3% (38.2–61.6%) | 29.8% (18.1–39.9%) |
Weighted Mean | 58.6% | 17.0% |