Background
Methods
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Weakness: Hand grip strength (HGS) was measured with participants sitting upright with the arm in flexion at 90 degrees. Three measurements were averaged from the participant’s dominant hand using a JAMAR Hydraulic Hand Dynamometer (Model J000105, Lafayette Instruments, Lafayette, IN, USA).
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Walking speed: Participants were asked to walk in a straight line, a distance of 4.5 m (15 ft). The distance was measured out on a flat floor surface using a rigid tape measure. The type of floor surface varied, for example participants who were assessed at their homes were often assessed walking outside due to limited space indoors. However, if the surface was slippery due to recent rain, or uneven, a surface indoors was found. At the local assessment centres (church buildings, dispensaries and local schools) smooth concrete floors were available. Walking speed was not adjusted for height or sex. Participants walked in their usual footwear and were permitted to use any walking aids.
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Exhaustion: A positive response was counted, to either of the two Centre for Epidemiological Studies Depression scale (CES-D) statements [13]: “I felt that everything I did was an effort” or “I could not get going”. These questions were translated verbatim to Swahili, and participants were asked to grade how often in the past week they had felt this way.
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Weight loss: Participants were asked “Have you lost weight during the last 3 months?” with the option of answering “Weight loss greater than 3kg”, “weight loss between 1 and 3kg”, “no weight loss” or “does not know”. This variable was turned from a categorical to a binary variable for analysis as described in Table 1. BMI was calculated from weight measured using Microlife Diagnostic WS 80 digital weighing scales and height using the Marsden Leicester Height Measure. Given that no serial measurements were possible, self-reported weight loss was preferred as a measure of unintentional weight loss.
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Low physical activity: The International Physical Activity Questionnaire (IPAQ), [14] was used to record participants’ estimations of their physical activity over the preceding 7 days. The IPAQ has been used widely, and in similar studies of older adults, for example the Ibadan study of ageing, from Nigeria [15]. Those who reported not being able to carry out tasks of moderate physical activity on any day of the previous week scored positively on this parameter. This was felt to be appropriate, given that carrying out “small works” in the home (such as using a winnowing basket or sharpening knives) was identified as a common norm for older adults in this context when developing a culturally adapted instrumental activities of daily living (IADLs) screening tool [16].
Component measured in both | Hai DSS frailty phenotype | Fried’s frailty phenotype |
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Weakness (low HGS): Average of three measurements in the dominant hand using the JAMAR hand-held dynamometer. | Frail criterion met if average HGS in the dominant hand <21Kg in males or < 10Kg in females based on the median HGS in African adults aged 61–70: 18 (10–25) women, 30 (21–38) men [21]. | Stratified by gender and body mass index (BMI) quartiles: Men Cut-off for grip strength (Kg) criterion for frailty BMI ≤ 24 ≤ 29 BMI 24.1–26 ≤ 30 BMI 26.1–28 ≤ 30 BMI > 28 ≤ 32 Women BMI ≤ 23 ≤ 17 BMI 23.1–26 ≤ 17.3 BMI 26.1–29 ≤ 18 BMI > 29 ≤ 21 |
Slow walking speed: Walking at usual pace, 4.5 m (15 ft) use of walking aid is permitted. | The slowest quintile of the sample’s walking speed was taken as cut-off: ≥11.12 s to walk 4.5 m distance (not stratified by gender or height). | Slowest quintile stratified by gender and height Men Height ≤ 173 cm ≥7 s Height > 173 cm ≥6 s Women Height ≤ 159 cm ≥7 s Height > 159 cm ≥6 s |
Self-reported exhaustion: CES–D Depression Scale questions were used. Frailty criterion if either was felt to be present a “moderate amount of the time” or “most of the time” over the past week. | The CES-D questions were verbatim translated into Swahili by a Tanzanian doctor and statements read aloud and scored in the same manner as the Fried FP. | CES–D Depression Scale questions, the following two statements are read. (a) I felt that everything I did was an effort; (b) I could not get going. Frailty criterion if either was felt to be present a “moderate amount of the time” or “most of the time” over the past week. |
Unintentional weight loss: | Has the participant/older person lost weight during the last 3 months? Frailty criterion were met if the participant answered either “yes, more than 3 kg”, or “yes, between 1 and 3 kg”. | “In the last year, have you lost more than 10 pounds unintentionally (i.e., not due to dieting or exercise)?” If yes, then frail for weight loss criterion, OR ≥5% of body weight lost in the past year unintentionally. |
Low physical activity | Taken from the IPAQ: “During the last 7 days, on how many days did you do moderate physical activities like gardening, cleaning, bicycling at a regular pace, swimming or other fitness activities?” Those who answered “0”, were categorised as meeting frailty criterion. | Based on the short version of the Minnesota Leisure Time Activity questionnaire Kcals per week expended are calculated using standardized algorithm. This variable is stratified by gender, with frailty criterion met if less than the lowest quintile of energy expended. Men: < 383 Kcals/week Women: < 270 Kcals/week. |
Frailty phenotype
Setting
Data analysis
Results
Prevalence of frailty
Impact of missing data on estimated frailty prevalence
Correlates of frailty by phenotype
Frequency (%) of frailty components | Total n = 196 | Males n = 82 | Females n = 114 |
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Exhaustion | 82 (41.82) | 32 (39.02) | 50 (43.86) |
Weight loss | 53 (27.04) | 23 (28.05) | 30 (26.32) |
Low physical activity | 48 (24.49) | 15 (18.29) | 33 (28.95) |
Slow walking | 39 (19.90) | 10 (12.20) | 29 (25.44) |
Weakness (Hand-grip strength) | 29 (14.80) | 22 (26.83) | 7 (6.14) |
Number of frailty components | |||
0 | 63 (32.14) | 31 (37.80) | 32 (28.07) |
1 | 67 (34.18) | 23 (28.05) | 44 (38.60) |
2 | 32 (16.33) | 15 (18.29) | 17 (14.91) |
3 | 18 (9.18) | 4 (4.88) | 14 (12.28) |
4 | 14 (7.14) | 8 (9.76) | 6 (5.26) |
5 | 2 (1.02) | 1 (1.22) | 1 (0.88) |
Demographic characteristic | Total sample n = 196 | FP not-frail n = 63 | FP pre-frail n = 99 | FP frail n = 34 | Pearson Chi2 (P value) for FP frailty vs FP not-frail/FP pre-frail |
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Age group | |||||
60–69 | 85 | 37 (43.53) | 43 (50.59) | 5 (5.88) | |
70–79 | 61 | 20 (32.79) | 31 (50.82) | 10 (16.39) | |
≥80 | 50 | 6 (12.00) | 25 (50.00) | 19 (38.00) |
22.705 (< 0.0001)
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Sex | |||||
Male | 82 | 31 (37.80) | 38 (46.34) | 13 (15.85) | |
Female | 114 | 32 (28.07) | 61 (53.51) | 21 (18.42) | 0.219 (0.640) |
Location where assessed | |||||
Elsewhere | 139 | 52 (37.41) | 76 (54.68) | 11 (7.91) | |
Home | 57 | 11 (19.30) | 23 (40.35) | 23 (40.35) |
29.664 (< 0.0001)
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Tribe | |||||
Mchagga | 176 | 59 (33.52) | 88 (50.00) | 29 (16.48) | |
Others | 20 | 4 (20.00) | 11 (55.00) | 5 (25.00) | 0.909 (0.340) |
Living arrangements | |||||
Lives with others | 174 | 56 (32.18) | 86 (49.43) | 32 (18.39) | |
Lives alone | 21 | 7 (33.33) | 12 (57.14) | 2 (9.52) | 1.023 (0.312) |
Marital status | |||||
Married | 97 | 39 (40.21) | 48 (49.48) | 10 (10.31) | |
Widowed, Separated/divorced or Single | 99 | 24 (24.24) | 51 (50.52) | 24 (24.24) |
6.633 (0.010)
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Education | |||||
Secondary and higher education | 16 | 11 (68.75) | 3 (18.75) | 2 (12.50) | |
Primary completed | 56 | 21 (37.50) | 31 (55.36) | 4 (7.14) | |
Some primary | 71 | 21 (29.58) | 37 (52.11) | 13 (18.31) | |
No school | 53 | 10 (18.87) | 28 (52.83) | 15 (28.30) |
8.811 (0.032)
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Literacy “Do you know how to read and write? (Yes if able/was able to read or write)” | |||||
Able to read/write well | 89 | 41 (46.07) | 39 (43.82) | 9 (10.11) | |
Read/write with difficulty | 52 | 13 (25.00) | 30 (57.69) | 9 (17.31) | |
Unable to read/write | 55 | 9 (16.36) | 30 (54.55) | 16 (29.09) |
8.539 (0.014)
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EURO-D score | |||||
Depression symptoms ≤3/12 | 105 | 43 (40.95) | 49 (46.67) | 13 (12.38) | |
Depression symptoms ≥4/12 | 91 | 20 (21.98) | 50 (54.95) | 21 (23.38) |
3.889 (0.049)
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IDEA cognitive test score | |||||
0–4 (poor cognitive function) | 20 | 2 (10.00) | 9 (45.00) | 9 (45.00) | |
5–7 (moderate cognitive function) | 37 | 6 (16.22) | 22 (59.46) | 9 (24.32) | |
8–12 (good cognitive function) | 139 | 55 (39.57) | 68 (48.92) | 16 (11.51) |
15.225 (< 0.0001)
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Functional ability | |||||
≥1 ADL disability | 47 | 5 (10.64) | 20 (42.55) | 22 (46.81) |
37.428 (< 0.0001)
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≥1 IADL disability | 60 | 8 (13.33) | 24 (40.00) | 28 (46.67) |
51.845 (< 0.0001)
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Healthcare provision | |||||
Health insurance | 51 | 19 (37.25) | 22 (43.14) | 10 (19.61) | |
No health insurance | 144 | 43 (29.86) | 77 (53.47) | 24 (16.67) | 0.226 (0.634) |
Ability to earn money or produce food | |||||
Working | 59 | 27 (45.76) | 31 (52.54) | 1 (1.69) | |
Not currently working | 137 | 36 (26.28) | 68 (49.64) | 33 (24.09) |
14.422 (< 0.0001)
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Household facilities | |||||
Electricity | 89 | 31 (34.83) | 38 (42.70) | 20 (22.47) | |
No electricity | 107 | 32 (29.91) | 61 (57.01) | 14 (13.08) | 2.986 (0.084) |
Provision for old age | |||||
Pension | 14 | 8 (57.14) | 5 (35.71) | 1 (7.14) | |
No pension | 182 | 55 (30.22) | 94 (51.65) | 33 (18.13) | 1.094 (0.295) |
“Do you consider yourself currently ill?” | |||||
Yes (Ill) | 119 | 17 (14.29) | 69 (57.98) | 33 (27.73) | |
No (not ill) | 77 | 46 (59.74) | 30 (38.96) | 1 (1.30) |
22.781 (< 0.0001)
|
“Do you consider yourself to be living with frailty currently?” | |||||
Yes (Frail) | 116 | 22 (18.97) | 65 (56.03) | 29 (25.00) | |
No (not frail) | 80 | 41 (51.25) | 34 (42.50) | 5 (6.25) |
11.609 (0.001)
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Self-assessed health: “How is your health?” | |||||
Good/Very good | 42 | 24 (57.14) | 16 (38.10) | 2 (4.76) | |
Neither good nor poor | 99 | 35 (35.35) | 51 (51.52) | 13 (13.13) | |
Poor/Very poor | 54 | 4 (7.41) | 31 (57.41) | 19 (35.19) |
17.778 (< 0.0001)
|
Self-reported medical diagnoses: “Have you ever been told you have a diagnosis of any of the following?” | |||||
Diabetes | 19 | 7 (36.84) | 8 (42.11) | 4 (21.05) | 0.201 (0.654) |
Hypertension | 58 | 18 (31.03) | 27 (46.55) | 13 (22.41) | 1.475 (0.225) |
Cataracts | 15 | 3 (20.00) | 6 (40.00) | 6 (40.00) |
5.747 (0.017)
|
Stroke | 8 | 1 (12.50) | 3 (37.50) | 4 (50.00) |
6.145 (0.013)
|
Heart disease | 11 | 4 (36.36) | 4 (36.36) | 3 (27.27) | 0.800 (0.371) |
Arthritis | 44 | 7 (15.91) | 24 (54.55) | 13 (29.55) |
5.788 (0.016)
|
Depression | 12 | 2 (16.67) | 8 (66.67) | 2 (16.67) | 0.004 (0.949) |
Chronic respiratory condition (asthma/COPD) | 13 | 4 (30.77) | 6 (46.15) | 3 (23.08) | 0.318 (0.572) |
Number of self-reported chronic diseases | |||||
0 | 70 | 27 (38.57) | 40 (57.14) | 3 (4.29) | |
1 | 67 | 24 (35.82) | 30 (44.78) | 13 (19.40) | |
≥2 | 59 | 12 (20.34) | 29 (49.15) | 18 (30.51) |
15.654 (< 0.0001)
|
BMI kg/m2 | |||||
Underweight (< 18.49) | 40 | 11 (27.50) | 24 (60.00) | 5 (12.50) | |
Normal weight (18.5–24.99) | 79 | 21 (26.58) | 41 (51.90) | 17 (21.52) | |
Overweight (25.00–29.99) | 54 | 22 (40.74) | 24 (44.44) | 8 (14.81) | |
Obese (≥30.00) | 21 | 9 (42.86) | 9 (42.86) | 3 (14.29) | 2.008 (0.571) |