| rowid | label_2 | w1 | w2 | w3 | w4 | w5 |
|---|---|---|---|---|---|---|
| 1 | R Self-report of health | 1 | 1 | 1 | 1 | 1 |
| 2 | R Ever had high blood pressure | 1 | 1 | 1 | 1 | 1 |
| 3 | R Ever had diabetes | 1 | 1 | 1 | 1 | 1 |
| 4 | R Ever had cancer | 1 | 1 | 1 | 1 | 1 |
| 5 | R Ever had respiratory disease, incl asthma | 1 | 1 | 1 | 1 | 1 |
| 6 | R Ever had heart attack | 1 | 1 | 1 | 1 | 1 |
| 7 | R Ever had stroke | 1 | 1 | 1 | 1 | 1 |
| 8 | R Ever had arthritis | 1 | 1 | 1 | 1 | 1 |
| 9 | R Self-rated eyesight | 1 | 1 | 1 | 1 | 1 |
| 10 | R Self-rated hearing | 1 | 1 | 1 | 1 | 1 |
| 11 | R Fallen down last 2 years | 1 | 1 | 1 | 1 | 1 |
| 12 | R Ever fractured a bone (including hip) since age 50 | 1 | 1 | 1 | 1 | NA |
| 13 | R Leaks urine when coughing (last 2 yrs) | NA | NA | 1 | 1 | 1 |
| 14 | R Difficulty breathing | 1 | 1 | 1 | 1 | 1 |
| 15 | R Severe fatigue | 1 | 1 | 1 | 1 | 1 |
| 16 | R Frequent problems with pain | 1 | 1 | 1 | 1 | 1 |
| 17 | R CESD-Felt depressed | 1 | 1 | 1 | 1 | 1 |
| 18 | R CESD-Everything an effort | 1 | 1 | 1 | 1 | 1 |
| 19 | R CESD-Sleep was restless | 1 | 1 | 1 | 1 | 1 |
| 20 | R CESD-Felt happy | 1 | 1 | 1 | 1 | 1 |
| 21 | R CESD-Felt lonely | 1 | 1 | 1 | 1 | 1 |
| 22 | R CESD-Felt sad | 1 | 1 | 1 | 1 | 1 |
| 23 | R CESD-Felt tired | 1 | 1 | 1 | 1 | 1 |
| 24 | R CESD-Had a lot of energy | 1 | 1 | 1 | 1 | 1 |
| 25 | R Difficulty-Dressing | 1 | 1 | 1 | 1 | 1 |
| 26 | R Difficulty-Walking across room | 1 | 1 | 1 | 1 | 1 |
| 27 | R Difficulty-Walking several blocks | 1 | 1 | 1 | 1 | 1 |
| 28 | R Difficulty-Picking up a coin | 1 | 1 | 1 | 1 | 1 |
| 29 | R Difficulty-Bathing or showering | 1 | 1 | 1 | 1 | 1 |
| 30 | R Difficulty-Eating | 1 | 1 | 1 | 1 | 1 |
| 31 | R Difficulty-Getting in/out of bed | 1 | 1 | 1 | 1 | 1 |
| 32 | R Difficulty-Using the toilet | 1 | 1 | 1 | 1 | 1 |
| 33 | R Difficulty-Managing money | 1 | 1 | 1 | 1 | 1 |
| 34 | R Difficulty-Taking medications | 1 | 1 | 1 | 1 | 1 |
| 35 | R Difficulty-Shopping for groceries | 1 | 1 | 1 | 1 | 1 |
| 36 | R Difficulty-Preparing hot meals | 1 | 1 | 1 | 1 | 1 |
Frailty Index: Mexican Health and Aging Study (MHAS)
1 Introduction
PURPOSE: To create a frailty index for MHAS”. Use available variables and create a frailty index using the accumulation of deficits approach.
- The deficit frailty index (FI) is defined as the proportion of deficits present in an observation out of the total number of age-related health variables considered.
- The process that Charlotte used to generate the frailty index in Longitudinal Health and Ageing Study (LASI) is outlined in the do file entitled
2_LASI_frailty_indices.dolocated in the J drive.
APPROACH:
- For MHAS, find out whether other studies have already created a frailty index and consider using the same approach
- Could otherwise base our index on the Health and Retirement Study (HRS) index or similar, but might need to modify it if any of the relevant variables haven’t been collected in MHAS
- Do some reading, come up with a plan and discuss and discuss with Charlotte before implementation.
BRIEF DESCRIPTION OF MHAS: - MHAS is a longitudinal population-based household survey in Mexico. We have data sets for 5 waves of data from 2001, 2003, 2012, 2015 and 2018. - Data sets are wide. All variables are named by wave, if not, then its not a time changing variable or not repeatedly measured, e.g race. - Household ID (cunicah), is the highest level of identification. - There is person number (np) which is the numerical order of persons in a household, so not unique per person in the survey, but unique per person within each household. - Each row of data therefore represents an observation in a household which is unique.
MHAS DATA SETS:
Harmonized MHAS: This is a cleaned, managed and research ready MHAS-data. It includes a selected set of variables and not exhaustive of all the variables in the MHAS study. It is a streamlined collection of variables derived from the Mexican Health and Aging Study (MHAS). The Harmonized MHAS data file incorporates data from the core interview data, the master follow-up file, household roster data, and next-of-kin data. It does not include any data which is not public release. for example, there is no data on infections exposure in the harmonized MHAS. CWG has already extracted the infections data and added to the harmonized MHAS data, file name
H_MHAS_c2_infections. This data is already loaded in thesetupcode chunk.Original MHAS: The full MHAS data set. Any variables not found in the harmonized data set can be found in the original/full MHAS data set. To extract a variable from the full MHAS data set, use the process CWG used.
2 Studies that developed and used the frailty index with MHAS data.
There are a number of studies that have created and validated the FI based on the accumulation of deficits approach. There is one by Garcia-Gonzales 2009 which was created in MHAS. Will use this study.
3 Brief overview of Garcia-Gonzales, etal, 2009 study:
3.1 Study design
- Objectives: To analyze relationships between the frailty index, age and mortality (outcome) in a two year follow up study of Mexican elderly.
- Population: 4082 adults 65+ years old, mean 73 years and 52.5% were women.
- Data source: MHAS waves 1 and 2, exposures in wave 1 (age, frailty Index), mortality wave 2.
- Weighted average frailty Index: 0.16, SD = 0.11
- Categorical frailty: Five levels of frailty: .00-.07, .07-.14, .14-.21, .21-.35, .35-.65
3.2 Calculation of frailty Index
Garcia used 34 deficits (variables). But its technically 45 as they combined some deficits into cumulative deficits e.g depressive symptoms included 9 deficits and Difficulty with mobility included 4 deficits. The deficits and coding can be found here Table 1 Health deficits included in the frailty index and their coding..
Five sub categories of deficits
- Health problems before age 10: will be excluded (6 deficits)
- General Health
- Medically diagnosed conditions
- Medical symptoms during the past 2 years
- Activities of daily living
- Instrumental activities of daily living
Coding was on the scoring system suggested by Rockwood et. al.
Complete case use: 145 observations were excluded due to missing frailty. It is not clear what minimum number of missing deficits were allowed. Looks like zero. Thus missing frailty meant at least one deficit was missing.
Frailty index was defined as a proportion of the total number of deficits an observation has with respect to the 34 deficits included. The denominator was observation-specific: done by taking the mean of the total score for each observation.
3.3 Categorical frailty in the literature
- FI score of 0.25 has construct and predictive validity to categorise community-dwelling older adults as frail or non-frail.
- Garcia used five levels for frailty categories. No binary categories was constructed for frail and not frail.
- In the literature 0.25 threshold has been mostly used for frail, not frail categorical frailty although some studies used 0.21.
4 Deficits to use in calculation
- Will use the following categories of deficits, excluding 6 deficits before age 10, yielding 28 deficits (34 - 6).
- General Health To be excluded
- Medically diagnosed conditions
- Medical symptoms during the past 2 years
- Activities of daily living
- Instrumental activities of daily living
- The 28 deficits = 39 variables in the data set.
- Depressive symptoms combines 9 deficits (depressed, unhappy, lonely, tired, sad, did not enjoy life, had no energy, restless sleep, or thought that everything did was an effort) and
- Difficulty with mobility combines 4 deficits, difficulty (picking up a coin, dressing, walking several blocks and walking across the room)
- For difficulty with mobility, each deficit will stand-alone in our calculation
5 What percentage of deficits are available and missing by wave in MHAS?
- 36/39 deficits available in Harmonised MHAS dataset
- 3 of remaining deficits in original MHAS
- so 39 deficits available, but not all are available in all waves
Reduces to
5.1 3 deficits NOT available in Harmonised MHAS dataset
First checked if available in MHAS survey questionnaires and found all
not found, Leg pain on walking (
c68h)not found, Stomach pain, indigestion or diarrhea (
c68f_wave)not found,
c49_6_wave: did not enjoy lifeExtract these variables from the original MHAS data set
Check from which waves these variables are available
| label | w1 | w2 | w3 | w4 | w5 |
|---|---|---|---|---|---|
| R Stomach pain, indigestion, diarrhea | 1 | 1 | 1 | 1 | 1 |
| R Pain in lower limbs while (or after) walking | 1 | 1 | NA | NA | NA |
| R enjoyed life | 1 | 1 | 1 | 1 | 1 |
| R Leaks urine when coughing (last 2 yrs) | 1 | 1 | 1 | 1 | 1 |
| R Ever fractured a bone (including hip) since age 50 | 1 | 1 | 1 | 1 | 1 |
6 How many deficits (distribution) are available by observation in each wave
Responses coded as .s are skipped questions, which means that people who have previously responded ‘no’ to a question like ‘do you have difficulty walking several blocks?’ will not be asked whether they have difficulty walking across a room.
In this case, we can impute their response to be ‘no’ to difficulty walking across a room.
These were largely the ADL questions.
Can see the criteria for skipped questions in the documentation of the section H functionality questionnaire (attached).
Also if Can’t Do or Don’t Do for the ADLs and IADLs, update to Yes (difficulty)
Which deficits have > 5% missing: Criteria for including a deficit/variable
Self-rated hearing is over 90% missing in wave 3: Although question has a skip condition, it is difficult to impute from the related questions.
To exclude.Leg pain on walking not available in waves 3-5:
To exclude.
| Characteristic1 | Wave_1 | Wave_2 | Wave_3 | Wave_4 | Wave_5 |
|---|---|---|---|---|---|
| N = 14,1541 | N = 12,5261 | N = 14,4481 | N = 13,8501 | N = 15,7861 | |
| 1. R Self-report of health | |||||
| 1.Excellent | 271 (1.9%) | 189 (1.5%) | 363 (2.5%) | 342 (2.5%) | 445 (2.8%) |
| 2.Very good | 627 (4.4%) | 396 (3.2%) | 646 (4.5%) | 465 (3.4%) | 796 (5.0%) |
| 3.Good | 4,495 (32%) | 3,559 (28%) | 4,303 (30%) | 3,710 (27%) | 4,670 (30%) |
| 4.Fair | 6,585 (47%) | 6,204 (50%) | 7,316 (51%) | 7,347 (53%) | 8,381 (53%) |
| 5.Poor | 2,169 (15%) | 2,173 (17%) | 1,817 (13%) | 1,983 (14%) | 1,491 (9.4%) |
| Missing | 7 (<0.1%) | 5 (<0.1%) | 3 (<0.1%) | 3 (<0.1%) | 3 (<0.1%) |
| 2. R Ever had high blood pressure | |||||
| 0.no | 8,552 (60%) | 6,583 (53%) | 7,126 (49%) | 5,787 (42%) | 7,279 (46%) |
| 1.yes | 5,176 (37%) | 5,915 (47%) | 7,292 (50%) | 8,049 (58%) | 8,496 (54%) |
| Missing | 426 (3.0%) | 28 (0.2%) | 30 (0.2%) | 14 (0.1%) | 11 (<0.1%) |
| 3. R Ever had diabetes | |||||
| 0.no | 11,609 (82%) | 10,112 (81%) | 11,024 (76%) | 10,095 (73%) | 11,516 (73%) |
| 1.yes | 2,129 (15%) | 2,368 (19%) | 3,395 (23%) | 3,739 (27%) | 4,245 (27%) |
| Missing | 416 (2.9%) | 46 (0.4%) | 29 (0.2%) | 16 (0.1%) | 25 (0.2%) |
| 4. R Ever had cancer | |||||
| 0.no | 13,483 (95%) | 12,208 (97%) | 13,996 (97%) | 13,312 (96%) | 15,160 (96%) |
| 1.yes | 266 (1.9%) | 290 (2.3%) | 429 (3.0%) | 525 (3.8%) | 614 (3.9%) |
| Missing | 405 (2.9%) | 28 (0.2%) | 23 (0.2%) | 13 (<0.1%) | 12 (<0.1%) |
| 5. R Ever had respiratory disease, incl asthma | |||||
| 0.no | 12,915 (91%) | 11,437 (91%) | 13,165 (91%) | 12,337 (89%) | 14,127 (89%) |
| 1.yes | 842 (5.9%) | 1,056 (8.4%) | 1,259 (8.7%) | 1,507 (11%) | 1,647 (10%) |
| Missing | 397 (2.8%) | 33 (0.3%) | 24 (0.2%) | 6 (<0.1%) | 12 (<0.1%) |
| 6. R Ever had heart attack | |||||
| 0.no | 13,312 (94%) | 11,937 (95%) | 13,711 (95%) | 12,964 (94%) | 14,750 (93%) |
| 1.yes | 439 (3.1%) | 573 (4.6%) | 716 (5.0%) | 879 (6.3%) | 1,028 (6.5%) |
| Missing | 403 (2.8%) | 16 (0.1%) | 21 (0.1%) | 7 (<0.1%) | 8 (<0.1%) |
| 7. R Ever had stroke | |||||
| 0.no | 13,418 (95%) | 12,169 (97%) | 14,010 (97%) | 13,334 (96%) | 15,224 (96%) |
| 1.yes | 325 (2.3%) | 350 (2.8%) | 424 (2.9%) | 504 (3.6%) | 554 (3.5%) |
| Missing | 411 (2.9%) | 7 (<0.1%) | 14 (<0.1%) | 12 (<0.1%) | 8 (<0.1%) |
| 8. R Ever had arthritis | |||||
| 0.no | 11,039 (78%) | 9,042 (72%) | 11,092 (77%) | 10,090 (73%) | 12,101 (77%) |
| 1.yes | 2,704 (19%) | 3,469 (28%) | 3,333 (23%) | 3,744 (27%) | 3,668 (23%) |
| Missing | 411 (2.9%) | 15 (0.1%) | 23 (0.2%) | 16 (0.1%) | 17 (0.1%) |
| 9. R Fallen down last 2 years | |||||
| 0.no | 9,133 (65%) | 7,948 (63%) | 8,819 (61%) | 7,716 (56%) | 9,327 (59%) |
| 1.yes | 5,004 (35%) | 4,568 (36%) | 5,623 (39%) | 6,124 (44%) | 6,456 (41%) |
| Missing | 17 (0.1%) | 10 (<0.1%) | 6 (<0.1%) | 10 (<0.1%) | 3 (<0.1%) |
| 10. R Ever fractured a bone (including hip) since age 50 | |||||
| 0.no | 10,858 (77%) | 3,518 (28%) | 11,667 (81%) | 10,711 (77%) | 453 (2.9%) |
| 1.yes | 1,595 (11%) | 859 (6.9%) | 2,357 (16%) | 2,994 (22%) | 14,416 (91%) |
| Missing | 1,701 (12%) | 8,149 (65%) | 424 (2.9%) | 145 (1.0%) | 917 (5.8%) |
| 11. R Self-rated eyesight | |||||
| 1.Excellent | 427 (3.0%) | 443 (3.5%) | 604 (4.2%) | 580 (4.2%) | 910 (5.8%) |
| 2.Very good | 1,363 (9.6%) | 893 (7.1%) | 1,168 (8.1%) | 909 (6.6%) | 1,366 (8.7%) |
| 3.Good | 6,029 (43%) | 5,577 (45%) | 6,203 (43%) | 5,815 (42%) | 5,879 (37%) |
| 4.Fair | 4,891 (35%) | 4,309 (34%) | 5,071 (35%) | 5,507 (40%) | 6,447 (41%) |
| 5.Poor | 1,295 (9.1%) | 1,171 (9.3%) | 1,014 (7.0%) | 979 (7.1%) | 1,097 (6.9%) |
| 6.Legally Blind | 44 (0.3%) | 53 (0.4%) | 41 (0.3%) | 47 (0.3%) | 49 (0.3%) |
| Missing | 105 (0.7%) | 80 (0.6%) | 347 (2.4%) | 13 (<0.1%) | 38 (0.2%) |
| 12. R Self-rated hearing | |||||
| 1.Excellent | 802 (5.7%) | 589 (4.7%) | 7 (<0.1%) | 673 (4.9%) | 1,215 (7.7%) |
| 2.Very good | 1,961 (14%) | 1,435 (11%) | 23 (0.2%) | 1,331 (9.6%) | 1,861 (12%) |
| 3.Good | 7,747 (55%) | 7,052 (56%) | 47 (0.3%) | 7,101 (51%) | 7,310 (46%) |
| 4.Fair | 2,774 (20%) | 2,631 (21%) | 67 (0.5%) | 4,121 (30%) | 4,757 (30%) |
| 5.Poor | 643 (4.5%) | 637 (5.1%) | 19 (0.1%) | 576 (4.2%) | 619 (3.9%) |
| 6.Legally Deaf | 13 (<0.1%) | 15 (0.1%) | 1 (<0.1%) | 3 (<0.1%) | 5 (<0.1%) |
| Missing | 214 (1.5%) | 167 (1.3%) | 14,284 (99%) | 45 (0.3%) | 19 (0.1%) |
| 13. R Severe fatigue | |||||
| 0.no | 10,315 (73%) | 9,294 (74%) | 11,282 (78%) | 10,928 (79%) | 12,777 (81%) |
| 1.yes | 3,803 (27%) | 3,229 (26%) | 3,158 (22%) | 2,910 (21%) | 2,996 (19%) |
| Missing | 36 (0.3%) | 3 (<0.1%) | 8 (<0.1%) | 12 (<0.1%) | 13 (<0.1%) |
| 14. R Difficulty breathing | |||||
| 0.no | 12,101 (85%) | 10,737 (86%) | 11,855 (82%) | 11,160 (81%) | 13,007 (82%) |
| 1.yes | 2,026 (14%) | 1,784 (14%) | 2,588 (18%) | 2,681 (19%) | 2,771 (18%) |
| Missing | 27 (0.2%) | 5 (<0.1%) | 5 (<0.1%) | 9 (<0.1%) | 8 (<0.1%) |
| 15. R Pain in lower limbs while (or after) walking | |||||
| 0.no | 8,179 (58%) | 7,139 (57%) | |||
| 1.yes | 5,942 (42%) | 5,221 (42%) | |||
| Missing | 33 (0.2%) | 166 (1.3%) | |||
| 16. R Stomach pain, indigestion, diarrhea | |||||
| 0.no | 11,389 (80%) | 9,901 (79%) | 11,312 (78%) | 10,703 (77%) | 12,532 (79%) |
| 1.yes | 2,734 (19%) | 2,459 (20%) | 3,129 (22%) | 3,129 (23%) | 3,245 (21%) |
| Missing | 31 (0.2%) | 166 (1.3%) | 7 (<0.1%) | 18 (0.1%) | 9 (<0.1%) |
| 17. R Frequent problems with pain | |||||
| 0.no | 8,298 (59%) | 7,594 (61%) | 8,935 (62%) | 8,532 (62%) | 9,561 (61%) |
| 1.yes | 5,838 (41%) | 4,929 (39%) | 5,508 (38%) | 5,314 (38%) | 6,218 (39%) |
| Missing | 18 (0.1%) | 3 (<0.1%) | 5 (<0.1%) | 4 (<0.1%) | 7 (<0.1%) |
| 18. R CESD-Felt depressed | |||||
| 0.No | 8,723 (62%) | 7,596 (61%) | 9,416 (65%) | 9,302 (67%) | 10,705 (68%) |
| 1.Yes | 5,284 (37%) | 4,907 (39%) | 5,011 (35%) | 4,528 (33%) | 5,065 (32%) |
| Missing | 147 (1.0%) | 23 (0.2%) | 21 (0.1%) | 20 (0.1%) | 16 (0.1%) |
| 19. R CESD-Everything an effort | |||||
| 0.No | 8,896 (63%) | 7,942 (63%) | 9,304 (64%) | 8,886 (64%) | 10,580 (67%) |
| 1.Yes | 5,088 (36%) | 4,568 (36%) | 5,122 (35%) | 4,947 (36%) | 5,181 (33%) |
| Missing | 170 (1.2%) | 16 (0.1%) | 22 (0.2%) | 17 (0.1%) | 25 (0.2%) |
| 20. R CESD-Sleep was restless | |||||
| 0.No | 8,898 (63%) | 7,620 (61%) | 8,391 (58%) | 8,002 (58%) | 9,218 (58%) |
| 1.Yes | 5,136 (36%) | 4,893 (39%) | 6,042 (42%) | 5,841 (42%) | 6,551 (41%) |
| Missing | 120 (0.8%) | 13 (0.1%) | 15 (0.1%) | 7 (<0.1%) | 17 (0.1%) |
| 21. R CESD-Felt happy | |||||
| 0.No | 3,437 (24%) | 3,382 (27%) | 2,923 (20%) | 2,606 (19%) | 3,064 (19%) |
| 1.Yes | 10,559 (75%) | 9,095 (73%) | 11,492 (80%) | 11,208 (81%) | 12,678 (80%) |
| Missing | 158 (1.1%) | 49 (0.4%) | 33 (0.2%) | 36 (0.3%) | 44 (0.3%) |
| 22. R CESD-Felt lonely | |||||
| 0.No | 9,407 (66%) | 8,409 (67%) | 10,086 (70%) | 9,648 (70%) | 11,153 (71%) |
| 1.Yes | 4,605 (33%) | 4,096 (33%) | 4,351 (30%) | 4,191 (30%) | 4,606 (29%) |
| Missing | 142 (1.0%) | 21 (0.2%) | 11 (<0.1%) | 11 (<0.1%) | 27 (0.2%) |
| 23. R CESD-Felt sad | |||||
| 0.No | 8,423 (60%) | 7,423 (59%) | 8,594 (59%) | 8,370 (60%) | 9,691 (61%) |
| 1.Yes | 5,583 (39%) | 5,091 (41%) | 5,839 (40%) | 5,465 (39%) | 6,069 (38%) |
| Missing | 148 (1.0%) | 12 (<0.1%) | 15 (0.1%) | 15 (0.1%) | 26 (0.2%) |
| 24. R enjoyed life | |||||
| 0.no | 3,975 (28%) | 3,917 (31%) | 3,296 (23%) | 2,888 (21%) | 3,429 (22%) |
| 1.yes | 9,943 (70%) | 8,384 (67%) | 11,117 (77%) | 10,913 (79%) | 12,306 (78%) |
| Missing | 236 (1.7%) | 225 (1.8%) | 35 (0.2%) | 49 (0.4%) | 51 (0.3%) |
| 25. R CESD-Felt tired | |||||
| 0.No | 5,665 (40%) | 5,331 (43%) | 5,906 (41%) | 5,536 (40%) | 6,602 (42%) |
| 1.Yes | 8,347 (59%) | 7,184 (57%) | 8,534 (59%) | 8,308 (60%) | 9,165 (58%) |
| Missing | 142 (1.0%) | 11 (<0.1%) | 8 (<0.1%) | 6 (<0.1%) | 19 (0.1%) |
| 26. R CESD-Had a lot of energy | |||||
| 0.No | 7,770 (55%) | 7,512 (60%) | 7,479 (52%) | 7,298 (53%) | 8,433 (53%) |
| 1.Yes | 6,168 (44%) | 4,958 (40%) | 6,940 (48%) | 6,531 (47%) | 7,305 (46%) |
| Missing | 216 (1.5%) | 56 (0.4%) | 29 (0.2%) | 21 (0.2%) | 48 (0.3%) |
| 27. R Difficulty-Picking up a coin | |||||
| 0.No | 13,324 (94%) | 11,785 (94%) | 13,391 (93%) | 12,796 (92%) | 14,469 (92%) |
| 1.Yes | 767 (5.4%) | 716 (5.7%) | 1,054 (7.3%) | 1,006 (7.3%) | 1,290 (8.2%) |
| Missing | 63 (0.4%) | 25 (0.2%) | 3 (<0.1%) | 48 (0.3%) | 27 (0.2%) |
| 28. R Difficulty-Dressing | |||||
| 0.No | 13,147 (93%) | 11,745 (94%) | 13,103 (91%) | 12,296 (89%) | 14,151 (90%) |
| 1.Yes | 901 (6.4%) | 756 (6.0%) | 1,340 (9.3%) | 1,506 (11%) | 1,608 (10%) |
| Missing | 106 (0.7%) | 25 (0.2%) | 5 (<0.1%) | 48 (0.3%) | 27 (0.2%) |
| 29. R Difficulty-Walking several blocks | |||||
| 0.No | 10,634 (75%) | 9,382 (75%) | 10,487 (73%) | 9,638 (70%) | 11,576 (73%) |
| 1.Yes | 3,464 (24%) | 3,118 (25%) | 3,957 (27%) | 4,166 (30%) | 4,187 (27%) |
| Missing | 56 (0.4%) | 26 (0.2%) | 4 (<0.1%) | 46 (0.3%) | 23 (0.1%) |
| 30. R Difficulty-Walking across room | |||||
| 0.No | 13,339 (94%) | 11,896 (95%) | 13,621 (94%) | 12,873 (93%) | 14,756 (93%) |
| 1.Yes | 601 (4.2%) | 581 (4.6%) | 790 (5.5%) | 928 (6.7%) | 982 (6.2%) |
| Missing | 214 (1.5%) | 49 (0.4%) | 37 (0.3%) | 49 (0.4%) | 48 (0.3%) |
| 31. R Difficulty-Bathing or showering | |||||
| 0.No | 13,529 (96%) | 12,110 (97%) | 13,946 (97%) | 13,142 (95%) | 15,134 (96%) |
| 1.Yes | 411 (2.9%) | 367 (2.9%) | 466 (3.2%) | 659 (4.8%) | 605 (3.8%) |
| Missing | 214 (1.5%) | 49 (0.4%) | 36 (0.2%) | 49 (0.4%) | 47 (0.3%) |
| 32. R Difficulty-Eating | |||||
| 0.No | 13,729 (97%) | 12,302 (98%) | 14,070 (97%) | 13,433 (97%) | 15,452 (98%) |
| 1.Yes | 211 (1.5%) | 175 (1.4%) | 342 (2.4%) | 368 (2.7%) | 287 (1.8%) |
| Missing | 214 (1.5%) | 49 (0.4%) | 36 (0.2%) | 49 (0.4%) | 47 (0.3%) |
| 33. R Difficulty-Getting in/out of bed | |||||
| 0.No | 13,289 (94%) | 11,943 (95%) | 13,420 (93%) | 12,632 (91%) | 14,774 (94%) |
| 1.Yes | 651 (4.6%) | 534 (4.3%) | 990 (6.9%) | 1,169 (8.4%) | 963 (6.1%) |
| Missing | 214 (1.5%) | 49 (0.4%) | 38 (0.3%) | 49 (0.4%) | 49 (0.3%) |
| 34. R Difficulty-Using the toilet | |||||
| 0.No | 13,481 (95%) | 12,113 (97%) | 13,715 (95%) | 13,099 (95%) | 14,924 (95%) |
| 1.Yes | 444 (3.1%) | 364 (2.9%) | 695 (4.8%) | 702 (5.1%) | 812 (5.1%) |
| Missing | 229 (1.6%) | 49 (0.4%) | 38 (0.3%) | 49 (0.4%) | 50 (0.3%) |
| 35. R Difficulty-Preparing hot meals | |||||
| 0.No | 12,841 (91%) | 11,404 (91%) | 13,190 (91%) | 12,560 (91%) | 14,701 (93%) |
| 1.Yes | 1,160 (8.2%) | 1,094 (8.7%) | 1,250 (8.7%) | 1,241 (9.0%) | 739 (4.7%) |
| Missing | 153 (1.1%) | 28 (0.2%) | 8 (<0.1%) | 49 (0.4%) | 346 (2.2%) |
| 36. R Difficulty-Shopping for groceries | |||||
| 0.No | 12,858 (91%) | 11,419 (91%) | 12,924 (89%) | 12,119 (88%) | 14,362 (91%) |
| 1.Yes | 1,158 (8.2%) | 1,080 (8.6%) | 1,516 (10%) | 1,682 (12%) | 1,392 (8.8%) |
| Missing | 138 (1.0%) | 27 (0.2%) | 8 (<0.1%) | 49 (0.4%) | 32 (0.2%) |
| 37. R Difficulty-Taking medications | |||||
| 0.No | 13,692 (97%) | 12,177 (97%) | 13,944 (97%) | 13,143 (95%) | 15,328 (97%) |
| 1.Yes | 364 (2.6%) | 323 (2.6%) | 501 (3.5%) | 659 (4.8%) | 425 (2.7%) |
| Missing | 98 (0.7%) | 26 (0.2%) | 3 (<0.1%) | 48 (0.3%) | 33 (0.2%) |
| 38. R Difficulty-Managing money | |||||
| 0.No | 13,693 (97%) | 12,188 (97%) | 14,056 (97%) | 13,321 (96%) | 15,350 (97%) |
| 1.Yes | 359 (2.5%) | 311 (2.5%) | 383 (2.7%) | 480 (3.5%) | 404 (2.6%) |
| Missing | 102 (0.7%) | 27 (0.2%) | 9 (<0.1%) | 49 (0.4%) | 32 (0.2%) |
| 39. R Leaks urine when coughing (last 2 yrs) | |||||
| 0.no | 13,023 (92%) | 11,256 (90%) | 12,203 (84%) | 11,204 (81%) | 13,088 (83%) |
| 1.yes | 1,098 (7.8%) | 1,098 (8.8%) | 2,234 (15%) | 2,633 (19%) | 2,682 (17%) |
| Missing | 33 (0.2%) | 172 (1.4%) | 11 (<0.1%) | 13 (<0.1%) | 16 (0.1%) |
| 1 Deficit 19 to 27 combines into one deficit of CESD-depressive symptoms so total deficits is 31 | |||||
7 Explore distribution of number of available deficits per observation by wave
Note: maximum number of deficits are actually 31 since 9 deficits combines into CESD-depressive symptoms.
| Characteristic | Wave_5 | Wave_4 | Wave_3 | Wave_2 | Wave_1 |
|---|---|---|---|---|---|
| N = 15,7861 | N = 13,8501 | N = 14,4481 | N = 12,5261 | N = 14,1541 | |
| Number of available deficits | |||||
| 31 | 4,200 (34%) | 11,407 (81%) | |||
| 30 | 14,404 (91%) | 13,514 (98%) | 157 (1.1%) | 7,889 (63%) | 1,895 (13%) |
| 29 | 1,282 (8.1%) | 265 (1.9%) | 13,354 (92%) | 166 (1.3%) | 173 (1.2%) |
| 28 | 31 (0.2%) | 17 (0.1%) | 850 (5.9%) | 85 (0.7%) | 42 (0.3%) |
| 27 | 5 (<0.1%) | 3 (<0.1%) | 36 (0.2%) | 125 (1.0%) | 27 (0.2%) |
| 26 | 8 (<0.1%) | 1 (<0.1%) | 3 (<0.1%) | 12 (<0.1%) | 141 (1.0%) |
| 25 | 22 (0.1%) | 4 (<0.1%) | 3 (<0.1%) | 22 (0.2%) | 35 (0.2%) |
| 24 | 4 (<0.1%) | 33 (0.2%) | 2 (<0.1%) | 308 (2.2%) | |
| 23 | 1 (<0.1%) | 6 (<0.1%) | 62 (0.4%) | ||
| 22 | 1 (<0.1%) | 4 (<0.1%) | 4 (<0.1%) | ||
| 21 | 1 (<0.1%) | 3 (<0.1%) | |||
| 20 | 1 (<0.1%) | ||||
| 19 | 4 (<0.1%) | 5 (<0.1%) | 40 (0.3%) | ||
| 18 | 19 (0.1%) | 35 (0.3%) | 14 (0.1%) | 7 (<0.1%) | |
| 17 | 2 (<0.1%) | 2 (<0.1%) | 1 (<0.1%) | 2 (<0.1%) | 2 (<0.1%) |
| 16 | 1 (<0.1%) | 2 (<0.1%) | |||
| 15 | 1 (<0.1%) | 1 (<0.1%) | 1 (<0.1%) | ||
| 14 | 5 (<0.1%) | 2 (<0.1%) | |||
| 12 | 1 (<0.1%) | ||||
| 11 | 1 (<0.1%) | ||||
| 9 | 1 (<0.1%) | ||||
| 5 | 1 (<0.1%) | ||||
| 3 | 1 (<0.1%) | ||||
| 1 | 1 (<0.1%) | 4 (<0.1%) | |||
| Categories | |||||
| <30 | 1,382 (8.8%) | 336 (2.4%) | 14,291 (99%) | 437 (3.5%) | 852 (6.0%) |
| >=30 | 14,404 (91%) | 13,514 (98%) | 157 (1.1%) | 12,089 (97%) | 13,302 (94%) |
| 1 n (%) | |||||
8 Create Frailty Index
Sum frailty deficit codes for each observation (i.e, for all deficits)
Then divide total score per observation by total number of included deficits (by wave)
Frailty Index Versions: based on number of deficits included due to deficit exceeding % missing threshold (i.e proportion of the deficit missing)
- Version 5% missing:
- In waves 1, 2, 3, 4, 5 … 1, 1, 1, 0, 1 deficits had >= 5% missing. Plus
R Pain in lower limbs while (or after) walkingnot available in waves 3 to 5 - Thus 30/31, 30/31, 29/31, 30/31, 29/31 deficits available in waves 1, 2, 3, 4, 5
- In waves 1, 2, 3, 4, 5 … 1, 1, 1, 0, 1 deficits had >= 5% missing. Plus
- Version 10% missing: same stats as with 5% missing cut-off
- Version 5% missing:
For cut-off by number of deficits missing per observation,
- Each observation must not have more than 20% of deficits missing
- Thus if >= 20% of deficits are missing by observation, Frailty Index = missing
- 20% of 31=5.8, 30=5.2,21=4.2, to round down to the nearest whole number
8.1 Check the specific deficits to exclude by wave based on missing thresholds
- Note: 5% and 10% missingness cut-off yields the same exclusions since variable missingness is >= 10%.
| No. | deficit | percent_missing |
|---|---|---|
| 1 | r1hip50e | 12.0178 |
| No. | deficit | percent_missing |
|---|---|---|
| 1 | r2hip50e | 65.05668 |
| No. | deficit | percent_missing |
|---|---|---|
| 1 | r3hearing | 98.86489 |
| 2 | r3walkpain | 100.00000 |
| No. | deficit | percent_missing |
|---|---|---|
| 1 | r4walkpain | 100 |
| No. | deficit | percent_missing |
|---|---|---|
| 1 | r5walkpain | 100 |
| No. | deficit | percent_missing |
|---|---|---|
| 1 | r1hip50e | 12.0178 |
| No. | deficit | percent_missing |
|---|---|---|
| 1 | r2hip50e | 65.05668 |
| No. | deficit | percent_missing |
|---|---|---|
| 1 | r3hearing | 98.86489 |
| 2 | r3walkpain | 100.00000 |
| No. | deficit | percent_missing |
|---|---|---|
| 1 | r4walkpain | 100 |
| No. | deficit | percent_missing |
|---|---|---|
| 1 | r5hip50e | 5.808945 |
| 2 | r5walkpain | 100.000000 |
8.2 Create Frailty Index: version 10% and 5% deficit missing cut-off
9 Distribution of frailty score by wave
- Row 1 is 10% deficit missing cut-off
- Row 2 is 5% deficit missing cut-off
| Characteristic | Wave1 | Wave2 | Wave3 | Wave4 |
|---|---|---|---|---|
| N = 14,1541 | N = 12,5261 | N = 14,4481 | N = 13,8501 | |
| frailty_10 | ||||
| Mean (SD) | 0.17 (0.12) | 0.18 (0.12) | 0.17 (0.12) | 0.20 (0.13) |
| Median (IQR) | 0.14 (0.08, 0.23) | 0.15 (0.09, 0.23) | 0.14 (0.08, 0.22) | 0.17 (0.11, 0.26) |
| Range | 0.00, 0.82 | 0.00, 0.81 | 0.00, 0.88 | 0.00, 0.84 |
| Missing | 434 | 27 | 12 | 46 |
| frailty_5 | ||||
| Mean (SD) | 0.17 (0.12) | 0.18 (0.12) | 0.17 (0.12) | 0.20 (0.13) |
| Median (IQR) | 0.14 (0.08, 0.23) | 0.15 (0.09, 0.23) | 0.14 (0.08, 0.22) | 0.17 (0.11, 0.26) |
| Range | 0.00, 0.82 | 0.00, 0.81 | 0.00, 0.88 | 0.00, 0.84 |
| Missing | 434 | 27 | 12 | 46 |
| frailty_10_cat | ||||
| Not Frail | 10,982 (78%) | 9,736 (78%) | 11,468 (79%) | 10,079 (73%) |
| Frail | 2,738 (19%) | 2,763 (22%) | 2,968 (21%) | 3,725 (27%) |
| Missing | 434 (3.1%) | 27 (0.2%) | 12 (<0.1%) | 46 (0.3%) |
| frailty_5_cat | ||||
| Not Frail | 10,982 (78%) | 9,736 (78%) | 11,468 (79%) | 10,079 (73%) |
| Frail | 2,738 (19%) | 2,763 (22%) | 2,968 (21%) | 3,725 (27%) |
| Missing | 434 (3.1%) | 27 (0.2%) | 12 (<0.1%) | 46 (0.3%) |
| 1 n (%) | ||||
10 Frailty distribution vs Garcia-Gonzales, etal, 2009 study
The frailty index by Garcia-Gonzales, etal, 2009 had an average value of 0.16 in the target population (standard deviation = 0.11), ranging in the sample from 0 to 0.65 and showing a right-skewed distribution. Figure is below.
Differences with Garcia-Gonzales, etal, 2009:
- 6 deficits excluded, medically diagnosed conditions before age 10,
with likely very low prevalence. This reduces denominator so makes sense wave 1 score slightly (0.02 points) higher. - Includes all ages thus 40+, against 65+ by Garcia
11 Codebook of frailty calculation
The table below summarizes the the methods and definitions for the frailty score estimation
| No. | Deficit description | Deficit coding | Deficit availability (or > 5% not missing) |
|---|---|---|---|
| 1 | R Self-report of health | Excellent = 0, Very good = 0.25, Good = 0.5, Fair = 0.75, Poor = 1 | waves 1, 2, 3, 4, 5 |
| 2 | R Ever had high blood pressure | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 3 | R Ever had diabetes | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 4 | R Ever had cancer | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 5 | R Ever had respiratory disease, incl asthma | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 6 | R Ever had heart attack | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 7 | R Ever had stroke | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 8 | R Ever had arthritis | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 9 | R Fallen down last 2 years | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 10 | R Ever fractured a bone (including hip) since age 50 | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 11 | R Self-rated eyesight | Excellent = 0, Very good = 0.2, Good = 0.4, Fair = 0.6, Poor = 0.8, Legally Blind = 1 | waves 1, 2, 3, 4, 5 |
| 12 | R Self-rated hearing | Excellent = 0, Very good = 0.2, Good = 0.4, Fair = 0.6, Poor = 0.8, Legally Deaf = 1 | waves 1, 2, 4, 5 |
| 13 | R Severe fatigue | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 14 | R Difficulty breathing | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 15 | R Pain in lower limbs while (or after) walking | No = 0, Yes = 1 | waves 1, 2 |
| 16 | R Stomach pain, indigestion, diarrhea | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 17 | R Frequent problems with pain | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 18 | R CESD-Felt depressed | No = 0, Yes = 1/9 | waves 1, 2, 3, 4, 5 |
| 19 | R CESD-Everything an effort | No = 0, Yes = 1/9 | waves 1, 2, 3, 4, 5 |
| 20 | R CESD-Sleep was restless | No = 0, Yes = 1/9 | waves 1, 2, 3, 4, 5 |
| 21 | R CESD-Felt happy | No = 1/9, Yes = 0 | waves 1, 2, 3, 4, 5 |
| 22 | R CESD-Felt lonely | No = 0, Yes = 1/9 | waves 1, 2, 3, 4, 5 |
| 23 | R CESD-Felt sad | No = 0, Yes = 1/9 | waves 1, 2, 3, 4, 5 |
| 24 | R enjoyed life | No = 1/9, Yes = 0 | waves 1, 2, 3, 4, 5 |
| 25 | R CESD-Felt tired | No = 0, Yes = 1/9 | waves 1, 2, 3, 4, 5 |
| 26 | R CESD-Had a lot of energy | No = 1/9, Yes = 0 | waves 1, 2, 3, 4, 5 |
| 27 | R Difficulty-Picking up a coin | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 28 | R Difficulty-Dressing | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 29 | R Difficulty-Walking several blocks | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 30 | R Difficulty-Walking across room | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 31 | R Difficulty-Bathing or showering | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 32 | R Difficulty-Eating | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 33 | R Difficulty-Getting in/out of bed | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 34 | R Difficulty-Using the toilet | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 35 | R Difficulty-Preparing hot meals | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 36 | R Difficulty-Shopping for groceries | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 37 | R Difficulty-Taking medications | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 38 | R Difficulty-Managing money | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| 39 | R Leaks urine when coughing (last 2 yrs) | No = 0, Yes = 1 | waves 1, 2, 3, 4, 5 |
| Total number of deficits available: waves 1, 2 = 39, wave 3 = 37, waves 4, 5 = 38. | |||
| 9 deficits coded each as Yes = 1/9 combines into one deficit = Depressive symptoms. | |||
| Thus total number of denominators (total deficits) in frailty score calculation is thus, 30 (waves 1 and 2), 29 (wave 3) and 30 (waves 4 and 5). | |||
| The final frailty score per observation in each wave = total number of deficits (sum) of that observation / denominator of that wave. | |||
12 Extract MHAS data for the different MSC projects
12.1 Aleixo’s project: Frailty trajectories in MHAS
12.1.1 Generate cognitive function variable by wave
Background - Cognitive function variable is not readily available but the MHAS group established the classification of cognitive function status using the combination of different conditions. There is a corresponding documentation with STATA code also available The Mexican Health and Aging Study:Cognitive Function Measures Scoring and Classification Across Waves. - The algorithm classifies an individual into one of 3 cognitive function categories; 1. normal 2. cognitive impairment no-dementia (CIND) and 3. dementia - the algorithms are specific to type of interviews but we are using those for direct interviews since this data extraction includes only direct interviews. - Cognitive function has been assessed in the MHAS using the screening portion of the Cross-Cultural Cognitive Examination (CCCE) for direct interviews (Glosser et al. 1993). - The CCCE has been modified over the MHAS waves to include a more comprehensive cognitive evaluation. - In 2001 (wave1), five tasks were included in the MHAS. - In 2003 (wave2), an additional task was included to measure orientation (marked in green in the list below). - In 2012 (wave3), semantic verbal fluency and backward counting tasks were added (marked in purple in the list below). - In 2015 (wave4), an additional task – serial 7 – was added (marked in red in the list below). - The tasks/variables used in calculating cognitive function are below.
- Constructional Praxis (visuo-constructional). measured by presenting two geometrical figures and asking respondents to copy the figures in 90 seconds.
- Verbal Fluency.
added in wave 3. measured by asking respondents to list all the animals they can think of in the next 60 seconds. - Serial 7s.
added in wave 4. measured by asking the respondent to sequentially subtract 7 starting from 100, until they complete five successive subtractions. - Verbal learning. measured by asking respondents to listen to a list of eight words and to repeat them.
- Visual scanning. measured by asking respondents to circle all figures that are identical to a specific stimulus shown previously within an array of different stimuli in 60 seconds.
- Backward Counting.
added in wave 3. measured by asking respondents to count backwards from 20 to 0 as fast as possible in 60 seconds. - Constructional Praxis Recall. measured by asking respondents to remember the figures they copied in 1 and to draw them from memory on a blank piece of paper in 3 minutes.
- Delayed Verbal recall. measured by asking respondents to repeat as many of the words they remember from the list provided in the verbal learning task.
- Day, Month and Year.
added in wave 2. This task asks respondents to indicate the day, month and year of the interview. - NOTE: If study aims to compare cognitive function across waves, it is recommended that only the first 5 tasks in wave 1 is used across waves.
Approach: Direct interviews
- Generate Z-score for each task.
- Define impairment for each task, based on Z score,
- Generate total number of tasks with impairment.
Individual should complete at least 2/5 of tasks included in wave1 else cognitive function set to missing. - Generate total number of difficulties with Instrumental Activities of Daily Living (IADL). Difficulty with meal preparation, shopping, taking medication and managing money.
- Classify cognitive function status as:
- Normal; No. of tasks with impairment = 0-1 and No. of difficulties with IADL = 0.
- CIND; No. of tasks with impairment = 2+ and No. of difficulties with IADL = 0.
- Dementia; No. of tasks with impairment = 2+ and No. of difficulties with IADL = 1-4.
cognitive function variable has been generated accordingly by MHAS and available for download here