Analyzed the data: AA NM. Wrote the paper: AA NM PK SC. Performed the study design: PK SC.
The authors have declared that no competing interests exist.
The World Health Organization (WHO) conducted the World Health Survey (WHS) between 2002 and 2004 in 70 countries to provide cross-population comparable data on health, health-related outcomes and risk factors. The aim of this study was to apply
This paper described the application of the GoM models to summarize population health status using World Health Survey data. Grade of Membership analysis is a flexible, non-parametric, multivariate method, used to calculate health profiles from WHS self-reported health state and health conditions. The WHS dataset was divided into four country economic categories based on the World Bank economic groupings (high, upper-middle, lower-middle and low income economies) for separate GoM analysis. Three main health profiles were produced for each of the four areas: I.
These analyses have provided a robust method to better understand health profiles and the components which can help to identify healthy and non-healthy individuals. The obtained profiles have described concrete levels of health and have clearly delineated characteristics of healthy and non-healthy respondents. The GoM results provided both a useable way of summarising complex individual health information and a selection of intermediate determinants which can be targeted for interventions to improve health. As populations' age, and with limited budgets for additional costs for health care and social services, applying the GoM methods may assist with identifying higher risk profiles for decision-making and resource allocations.
Currently, the concept of health as defined by the World Health Organization (WHO) is “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity”
GoM is a non-parametric method that identifies latent health profiles and the degree to which an individual fits these profiles. The GoM method has been applied in previous studies for depressive symptoms and personality disorders
The WHO's World Health Survey (WHS) gather data to quantify population health status in 70 countries based on WHO's definition of health. The main aim of this study was to summarize, using the
This paper is organized into three sections. First, a description of the data set is provided, which includes details of the survey design, socio-demographic characteristics of the sample and health data. Then the GoM procedure and results of the GoM analysis are described for each economic category. The final section summarizes the results.
The WHS was conducted between 2002 and 2004 in 70 countries to establish levels of health and to develop methods to improve data comparability within and across countries
A probability sampling design was employed in each country using multi-stage, stratified, random cluster samples. The population included all selected persons aged 18 years and older who lived in selected households. Most of the countries had nationally representative survey samples and each country decided which interview method to use: face-to-face interview, computer-assisted telephone interview (CATI) and/or computer-assisted personal interview (CAPI).
The WHS utilized two types of questionnaires: the
High Income Countries | Upper-middle Income Countries | Lower-middle Income Countries | Low Income Countries |
Australia | Croatia | Bosnia and Herzegovina | Bangladesh |
Austria | Brazil | China | Burkina Faso |
Belgium | Hungary | Congo | Chad |
Czech Republic | Kazakhstan | Dominican Republic | Comoros |
Denmark | Latvia | Ecuador | Côte d'Ivoire |
Estonia | Malaysia | Georgia | Ethiopia |
Finland | Mauritius | Guatemala | Ghana |
France | Mexico | Morocco | India |
Germany | Russian Federation | Namibia | Kenya |
Greece | Slovakia | Paraguay | Lao People's Democratic Republic |
Ireland | South Africa | Philippines | Malawi |
Israel | Uruguay | Sri Lanka | Mali |
Italy | Swaziland | Mauritania | |
Luxembourg | Tunisia | Myanmar | |
Netherlands | Ukraine | Nepal | |
Norway | Pakistan | ||
Portugal | Senegal | ||
Slovenia | Vietnam | ||
Spain | Zambia | ||
Sweden | Zimbabwe | ||
United Arab Emirates | |||
United Kingdom | |||
22 | 12 | 15 | 20 |
The World Bank's uses gross national income (GNI) per capita as its main criterion for classifying economies. Based on its 2006 GNI per capita, every country's economy was classified as low income, middle income (subdivided into lower middle and upper middle), or high income. The four groups are defined as: low income, $905 or less; lower middle income, $906–$3595; upper middle income, $3596–$11,115; and high income, $11,116 or more.
The dataset included self-reported diagnosis of three physical and one mental health condition (arthritis, angina pectoris, asthma and depression), self-reported difficulties in functioning in eight health domains (mobility, self-care, pain and discomfort, cognition, interpersonal relationships, vision, sleep and energy, and affect) plus one self-reported overall health question. Presence or absence of a diagnosed condition was based on self-report.
Grade of Membership (GoM) model
Briefly, as outlined in Manton et al
By summing over all potential GoM health pure types:
Assuming independence of individual observations, the likelihood function for the GoM model is:
We used the DSIGoM software
The optimal number of profiles is established by performing a likelihood ratio test on the change in explanatory power between
Prior to analyzing data, it was necessary to define the external and the internal variables
The continuous age variable was recoded into three categories: younger adult (18–29 years); adult (30–59 years), and older adult (60 years and older). Marital status was recoded into four categories: never married, currently married/cohabiting, separated/divorced and widowed. Sex, education levels (highest level completed) and sector of current employment (governmental, non-governmental, self-employed, employer, homemaker, unemployed, student, retired and other) were the remaining external variables.
Internal variables included self-reported overall health (based on a five point scale: very good, good, moderate, bad or very bad), scores from the eight health domains (none, mild, moderate, severe or extreme/cannot do), and the set of four reported conditions (yes, no).
For each of the four country categories, the GoM analysis was applied with 2, 3 and 4 pure types to test for the optimal number of pure types. The GoM parameters estimation was derived using the DSIGoM software. Log likelihood ratio test indicated that three pure types provided the best description of the structure of the variables included in this analysis for each economic area. Each pure type was described by the values obtained for the λ coefficients. In general, λ
In order to compare the prevalence rates across the four groups, age-standardized prevalence estimates were calculated. For each pure type and economic category, age-specific (younger adult 18–29, adult 30–59, and older adult 60+) prevalence ratios were computed. To calculate adjusted age-specific prevalence rates we used the direct standardization method with the WHO world standard population table
The final dataset contained 217,472 respondents from 69 countries. These countries were grouped into the four World Bank income categories for analysis. The socio-demographic characteristics of the respondents are provided in
Variables | HIGH INCOME | UPPER MIDDLE INCOME | LOWER MIDDLE INCOME | LOW INCOME | p-value |
(N = 26358) | (N = 51090) | (N = 58799) | (N = 81225) | (Χ2) | |
Sex | <0.0001 | ||||
Female | 50.60 | 52.94 | 51.02 | 49.49 | |
Male | 49.40 | 47.06 | 48.98 | 50.51 | |
Age | <0.0001 | ||||
18–19 | 3.57 | 5.88 | 5.77 | 8.09 | |
20–29 | 17.76 | 26.27 | 27.37 | 32.21 | |
30–39 | 18.84 | 21.68 | 20.91 | 21.77 | |
40–49 | 18.95 | 18.42 | 18.42 | 16.02 | |
50–59 | 15.91 | 12.34 | 12.25 | 10.99 | |
60–69 | 10.72 | 8.19 | 8.73 | 6.80 | |
70+ | 14.25 | 7.21 | 6.55 | 4.13 | |
Marital Status | <0.0001 | ||||
Never Married | 22.82 | 26.88 | 25.40 | 21.78 | |
Currently Married | 54.12 | 48.72 | 58.22 | 69.98 | |
Separated | 2.29 | 3.07 | 1.60 | 0.79 | |
Divorced | 5.03 | 3.58 | 2.19 | 1.12 | |
Widowed | 8.58 | 8.01 | 7.17 | 6.00 | |
Cohabiting | 7.15 | 9.74 | 5.42 | 0.33 | |
Education | <0.0001 | ||||
No formal schooling | 2.44 | 7.01 | 9.73 | 40.09 | |
Less than primary school | 5.88 | 7.82 | 9.76 | 13.30 | |
Primary school completed | 16.66 | 21.77 | 21.14 | 19.71 | |
Secondary school completed | 23.67 | 27.04 | 23.96 | 13.45 | |
High school(or equivalent) completed | 27.48 | 24.31 | 19.67 | 7.39 | |
College/pre-university/University completed | 16.68 | 10.34 | 15.18 | 5.09 | |
Post graduate degree completed | 7.21 | 1.72 | 0.55 | 0.96 | |
Current job | <0.0001 | ||||
Government employee | 14.46 | 14.64 | 12.79 | 4.05 | |
Private sector employee | 39.90 | 23.56 | 16.98 | 7.50 | |
Self-employed | 6.12 | 19.60 | 19.54 | 45.80 | |
Employer | 1.60 | 2.57 | 2.17 | 0.70 | |
Homemaker | 10.08 | 10.25 | 20.84 | 27.14 | |
Looked but can't find a job | 3.74 | 8.79 | 7.88 | 3.04 | |
Studies | 7.49 | 3.64 | 5.40 | 4.38 | |
Retired | 13.77 | 11.94 | 10.03 | 4.17 | |
Other | 2.84 | 5.01 | 4.36 | 3.22 |
Three country categories (high, upper-middle and lower-middle income) had more women than the other group (low income), although the subdivision between males and females is almost symmetric for every region. More young respondents (aged 20–29 years) were noted in the upper-middle, lower-middle and low income categories. The higher income categories had more old respondents than the other groups. The low income category had a higher percentage (8.1%) of the youngest respondents (aged 18–19 years), while the high income category had the highest percentage of older adults with 14.2% of individuals aged 70+ years. Respondents in the low income category were more likely to be currently married (70%) and had the highest levels of respondents with no formal education (40.1%). The high income category had the highest education rate. Current employment sector/issues differed by category: the two highest income categories (high and upper-middle income) had more respondents employed in the private sector (39.9% and 23.6% respectively). The lower-middle income category had more homemakers and self-employed (20.8% and 19.5%) while low income countries had higher levels of self-employed (45.8%). The category with the most retired respondents was the high income (13.8%). An association between all socio-demographic characteristics and the four economic country categories was found (p<0.0001).
The internal variables in the GoM analysis included self-reported physical and mental health data. Descriptive statistics of these variables for the four economic categories were provided in
Variables | HIGH INCOME | UPPER MIDDLE INCOME | LOWER MIDDLE INCOME | LOW INCOME | p-value | ||
(N = 26358) | (N = 51090) | (N = 58799) | (N = 81225) | (Χ2) | |||
Health Status | <0.0001 | ||||||
Very Good | 23.65 | 17.11 | 13.99 | 25.05 | |||
Good | 46.42 | 40.99 | 39.47 | 38.92 | |||
Moderate | 22.23 | 33.20 | 35.38 | 26.62 | |||
Bad | 6.66 | 7.18 | 9.23 | 8.06 | |||
Very Bad | 1.05 | 1.52 | 1.93 | 1.35 | |||
Difficulty moving around | <0.0001 | ||||||
None | 75.72 | 72.71 | 61.12 | 65.05 | |||
Mild | 9.75 | 11.61 | 15.75 | 18.36 | |||
Moderate | 9.14 | 9.73 | 17.15 | 10.00 | |||
Severe | 4.48 | 4.94 | 5.18 | 5.39 | |||
Extreme/Cannot do | 0.91 | 1.02 | 0.81 | 1.20 | |||
Difficulty in Self-Care | <0.0001 | ||||||
None | 89.56 | 87.96 | 79.73 | 78.63 | |||
Mild | 5.16 | 5.82 | 9.39 | 12.53 | |||
Moderate | 3.40 | 3.82 | 8.52 | 5.37 | |||
Severe | 1.41 | 1.79 | 1.81 | 2.52 | |||
Extreme/Cannot do | 0.47 | 0.61 | 0.55 | 0.96 | |||
Pain and discomfort | <0.0001 | ||||||
None | 52.14 | 46.20 | 44.64 | 47.53 | |||
Mild | 24.55 | 23.80 | 25.06 | 27.38 | |||
Moderate | 14.97 | 18.47 | 19.24 | 14.10 | |||
Severe | 7.31 | 8.76 | 9.51 | 9.01 | |||
Extreme | 1.03 | 2.77 | 1.55 | 1.97 | |||
Difficulty in concentration | <0.0001 | ||||||
None | 69.55 | 61.99 | 59.41 | 64.45 | |||
Mild | 17.98 | 19.30 | 19.82 | 19.43 | |||
Moderate | 9.36 | 11.76 | 15.12 | 9.76 | |||
Severe | 2.67 | 5.73 | 4.80 | 5.12 | |||
Extreme/Cannot do | 0.44 | 1.22 | 0.84 | 1.25 | |||
Difficulty in personal relationships | <0.0001 | ||||||
None | 85.48 | 81.34 | 71.50 | 77.84 | |||
Mild | 8.55 | 9.99 | 14.63 | 13.23 | |||
Moderate | 4.22 | 5.82 | 11.21 | 5.29 | |||
Severe | 1.44 | 2.00 | 1.98 | 2.34 | |||
Extreme/Cannot do | 0.31 | 0.85 | 0.67 | 1.31 | |||
Difficulty in seeing and recognizing persons | <0.0001 | ||||||
None | 83.83 | 78.33 | 73.95 | 79.65 | |||
Mild | 8.88 | 9.91 | 11.88 | 10.19 | |||
Moderate | 4.64 | 6.74 | 8.78 | 5.27 | |||
Severe | 1.96 | 3.60 | 4.30 | 3.50 | |||
Extreme/Cannot do | 0.70 | 1.41 | 1.08 | 1.39 | |||
Sleeping disorders | <0.0001 | ||||||
None | 58.95 | 60.95 | 56.48 | 65.37 | |||
Mild | 19.47 | 17.34 | 20.46 | 18.12 | |||
Moderate | 14.15 | 12.63 | 15.18 | 9.59 | |||
Severe | 6.08 | 7.05 | 6.77 | 5.41 | |||
Extreme | 1.35 | 2.03 | 1.11 | 1.50 | |||
Feeling sad or depressed | <0.0001 | ||||||
None | 64.06 | 53.89 | 54.20 | 59.57 | |||
Mild | 19.71 | 21.68 | 23.37 | 22.00 | |||
Moderate | 10.86 | 14.48 | 14.91 | 10.74 | |||
Severe | 4.41 | 7.20 | 6.28 | 5.99 | |||
Extreme | 0.95 | 2.75 | 1.24 | 1.70 | |||
Diagnosis of Arthritis | <0.0001 | ||||||
No | 86.88 | 90.15 | 86.53 | 85.83 | |||
Yes | 13.12 | 9.85 | 13.47 | 14.17 | |||
Diagnosis of Angina Pectoris | <0.0001 | ||||||
No | 95.17 | 92.56 | 91.91 | 93.48 | |||
Yes | 4.83 | 7.44 | 8.09 | 6.52 | |||
Diagnosis of Asthma | <0.0001 | ||||||
No | 90.18 | 93.29 | 94.57 | 95.95 | |||
Yes | 9.82 | 6.71 | 5.43 | 4.05 | |||
Diagnosis of Depression | <0.0001 | ||||||
No | 85.88 | 90.05 | 96.09 | 94.88 | |||
Yes | 14.12 | 9.95 | 3.91 | 5.12 |
The majority of the respondents reported good or very good health status for the self-reported overall general health question, with the lower-middle income category having the highest percentage of respondents reporting a bad or very bad health status. In all the eight health domains (mobility, self-care, pain and discomfort, cognition, interpersonal relationships, vision, sleep and energy, and affect), the prevalence rates followed a positive trend. The majority of the respondents (more than 50%) reported no difficulties on any of the physical or mental health issues, with the exception of the domain “pain and discomfort”, where prevalence rates ranged from 44.6% of lower-middle income category to 52.1% of high income group. Finally, over 85% of respondents reported no diagnosed health conditions (arthritis, angina pectoris, asthma and depression). Among these conditions, it was noted that the low income category had the highest percentage (14.2%) of respondents with arthritis, the lower-middle income group had the highest percentage (8.1%) with angina pectoris, and the high income category had the highest percentage with asthma and depression (9.8% and 14.1%, respectively).
Profile (Pure type) | Variables | High Income | Upper Middle Income | Lower Middle Income | Low Income |
I: ROBUST | SRH | Good | Good | Good | Good |
HS | None | None | None | None | |
CC | None | None | None | None | |
II: INTERMEDIATE | SRH | Good | Moderate | Moderate | Moderate |
HS | Some | Some | Some | Some | |
CC | None | None | None | None | |
III: FRAIL | SRH | Moderate | Moderate | Moderate | Moderate |
HS | More | More | More | More | |
CC | Arthritis, Depression | Arthritis | None | Arthritis |
SRH = Self-reported overall general health (“In general, how would you rate your health today?”), HS = health state determined by level of difficulty with each of the eight health domains, CC = reported chronic conditions: arthritis, angina pectoris, asthma and/or depression.
Similarly, the lambda probability variables for each of the external variables by country category show discernable patterns for each of the health profiles (
Profile (Pure type) | Variables | High Income | Upper-middle Income | Lower-middle Income | Low Income |
I: ROBUST | Sex | Female/Male | Male | Male | Male |
Age group | Adult | Adult | Adult | Young/Adult | |
Marital status | Married | Married | Married | Married | |
Education | High | Intermediate | Low | None | |
Current job | Private sector | Self-employed | Self-employed | Self-employed | |
II: INTERMEDIATE | Sex | Female | Female | Female | Female |
Age group | Adult | Adult | Adult | Adult | |
Marital status | Married | Married | Married | Married | |
Education | High | Intermediate | Low | None | |
Current job | Private sector | Self-employed | Homemaker | Self-employed | |
III: FRAIL | Sex | Female | Female | Female | Female |
Age group | Older | Older | Older | Adult | |
Marital status | Married | Married | Married | Married | |
Education | Low | Low/Intermediate | None | None | |
Current job | Retired | Retired | Homemaker | Self-employed |
GoM range |
I | II | III | |||
% | % | % | ||||
0 | 2958 | 11.22 | 10958 | 41.57 | 12614 | 47.86 |
0.01–0.25 | 1800 | 6.83 | 4957 | 18.81 | 6209 | 23.56 |
0.26–0.50 | 4660 | 17.68 | 6045 | 22.93 | 3785 | 14.36 |
0.51–0.75 | 6009 | 22.80 | 3192 | 12.11 | 2229 | 8.46 |
0.76–0.99 | 5117 | 19.41 | 960 | 3.64 | 933 | 3.54 |
1 | 5814 | 22.06 | 246 | 0.93 | 588 | 2.23 |
Age-standardized prevalence (%) |
GoM scores range from 0 (no membership in that health profile) to 1 (exclusive membership in that health profile).
Freq (%) | I | II | III | |
Sex | ||||
Female | 57.56 | |||
Male | 42.44 | 35.85 | 25.29 | |
Age | ||||
Young Adult (18–29) | 17.21 | 23.30 | 15.06 | 1.26 |
Adult (30–59) | 53.97 | 29.84 | ||
Old Adult (60+) | 28.83 | 14.13 | 32.60 | |
Marital status | ||||
Never Married | 20.57 | 25.98 | 18.27 | 5.96 |
Currently married/Cohabiting | 59.98 | |||
Separated/Divorced | 8.89 | 7.23 | 10.76 | 11.99 |
Widowed | 10.55 | 3.34 | 12.11 | 31.89 |
Education | ||||
No formal schooling | 2.57 | 0.75 | 2.01 | 9.02 |
Less than primary school | 5.68 | 2.30 | 5.15 | 17.04 |
Primary school completed | 14.74 | 10.67 | 13.45 | |
Secondary school completed | 28.03 | 23.85 | 26.45 | |
High school (or equivalent) completed | 27.12 | 13.48 | ||
College/pre-university/University completed | 17.64 | 19.70 | 23.60 | 4.12 |
Post graduate degree completed | 4.22 | 5.37 | 4.05 | 0.72 |
Current job | ||||
Government employee | 14.03 | 17.48 | 15.37 | 2.15 |
No government employee | 29.41 | 5.04 | ||
Self-employed | 6.86 | 8.52 | 6.72 | 2.00 |
Employer | 1.95 | 2.55 | 1.64 | 0.48 |
Homemaker | 13.13 | 11.51 | 11.39 | 20.00 |
Looked but can't find a job | 3.13 | 3.64 | 2.90 | 1.88 |
Studies | 5.08 | 6.56 | 5.47 | 0.20 |
Retired | 22.02 | 10.48 | 25.42 | |
Other | 4.38 | 1.43 | 2.57 | 15.33 |
Health Status | ||||
Very Good | 25.00 | 45.02 | 0.00 | 0.00 |
Good | 43.13 | 0.00 | ||
Moderate | 24.38 | 0.00 | 39.41 | |
Bad | 6.23 | 0.00 | 0.00 | 26.30 |
Very Bad | 1.26 | 0.00 | 0.00 | 5.34 |
Difficulty moving around | ||||
None | 71.87 | 46.99 | 0.00 | |
Mild | 12.28 | 0.00 | 0.00 | |
Moderate | 10.33 | 0.00 | 0.00 | |
Severe | 4.69 | 0.00 | 0.00 | 29.57 |
Extreme/Cannot do | 0.83 | 0.00 | 0.00 | 5.22 |
Difficulty in Self-Care | ||||
None | 89.86 | |||
Mild | 5.18 | 0.00 | 0.00 | |
Moderate | 3.40 | 0.00 | 0.00 | 22.10 |
Severe | 1.24 | 0.00 | 0.00 | 8.05 |
Extreme/Cannot do | 0.33 | 0.00 | 0.00 | 2.15 |
Pain and discomfort | ||||
None | 48.92 | 0.00 | 0.00 | |
Mild | 25.35 | 0.00 | 0.00 | |
Moderate | 16.81 | 0.00 | 0.00 | |
Severe | 7.82 | 0.00 | 0.00 | 30.38 |
Extreme | 1.10 | 0.00 | 0.00 | 4.28 |
Difficulty in concentration | ||||
None | 68.32 | 0.00 | 0.00 | |
Mild | 19.56 | 0.00 | 0.00 | |
Moderate | 9.11 | 0.00 | 0.00 | |
Severe | 2.69 | 0.00 | 0.00 | 22.19 |
Extreme/Cannot do | 0.33 | 0.00 | 0.00 | 2.69 |
Difficulty in personal relationships | ||||
None | 83.19 | |||
Mild | 9.97 | 0.00 | 32.80 | 19.13 |
Moderate | 4.69 | 0.00 | 0.00 | 29.95 |
Severe | 1.74 | 0.00 | 0.00 | 11.13 |
Extreme/Cannot do | 0.41 | 0.00 | 0.00 | 2.64 |
Difficulty in seeing and recognizing persons | ||||
None | 84.08 | |||
Mild | 8.87 | 0.00 | 28.15 | 13.26 |
Moderate | 4.50 | 0.00 | 0.00 | 25.60 |
Severe | 1.97 | 0.00 | 0.00 | 11.19 |
Extreme/Cannot do | 0.59 | 0.00 | 0.00 | 3.37 |
Sleeping disorders | ||||
None | 56.66 | 0.00 | 0.00 | |
Mild | 20.31 | 0.00 | 0.00 | |
Moderate | 14.53 | 0.00 | 18.68 | |
Severe | 7.17 | 0.00 | 0.00 | 39.06 |
Extreme | 1.33 | 0.00 | 0.00 | 7.23 |
Feeling sad or depressed | ||||
None | 62.13 | 0.00 | 0.00 | |
Mild | 20.78 | 0.00 | 0.00 | |
Moderate | 11.42 | 0.00 | 0.00 | |
Severe | 4.73 | 0.00 | 0.00 | 27.67 |
Extreme | 0.94 | 0.00 | 0.00 | 5.52 |
Diagnosis of Arthritis | ||||
No | 84.21 | 38.46 | ||
Yes | 15.79 | 0.00 | 16.36 | |
Diagnosis of Angina Pectoris | ||||
No | 93.87 | |||
Yes | 6.13 | 0.00 | 0.00 | 31.78 |
Diagnosis of Asthma | ||||
No | 89.81 | |||
Yes | 10.19 | 5.08 | 13.97 | 22.21 |
Diagnosis of Depression | ||||
No | 87.87 | 39.70 | ||
Yes | 12.13 | 0.00 | 0.00 |
Individuals in pure type II differed from those in pure type I in that they were mainly female (64.1%) and had some difficulty with physical and mental activities, especially moving around (53%), pain and discomfort (100%), concentration (100%), sleeping (81.3%), feeling sad or depressed (100%).
Finally, respondents in pure type III were mainly female (74.7%), old (68.9%), married or cohabiting (50.2%), less educated (29.2%), and retired (52.9%). They reported moderate health status (68.4%) and had more difficulty with physical and mental activities, especially moving around (65.2%), pain and discomfort (65.3%), concentration (75.1%), sleeping (53.7%), feeling sad or depressed (66.8%). Moreover they reported having arthritis (61.5%) and depression (60.3%).
GoM range |
I | II | III | |||
% | % | % | ||||
0 | 5025 | 9.84 | 19597 | 38.36 | 27889 | 54.59 |
0.01–0.25 | 3103 | 6.07 | 11352 | 22.22 | 10866 | 21.27 |
0.26–0.50 | 7753 | 15.18 | 11844 | 23.18 | 6675 | 13.07 |
0.51–0.75 | 11861 | 23.22 | 6147 | 12.03 | 3301 | 6.46 |
0.76–0.99 | 10795 | 21.13 | 1712 | 3.35 | 1410 | 2.76 |
1 | 12553 | 24.57 | 438 | 0.86 | 949 | 1.86 |
Age-standardized prevalence (%) |
GoM scores range from 0 (no membership in that health profile) to 1 (exclusive membership in that health profile).
Freq (%) | I | II | III | |
Sex | ||||
Female | 47.70 | 36.21 | ||
Male | 52.30 | 39.96 | 23.72 | |
Age | ||||
Young Adult (18–29) | 25.45 | 34.01 | 17.35 | 1.60 |
Adult (30–59) | 59.85 | 43.14 | ||
Old Adult (60+) | 14.70 | 4.75 | 15.26 | |
Marital status | ||||
Never Married | 20.81 | 25.76 | 16.02 | 7.04 |
Currently married/Cohabiting | 62.85 | |||
Separated/Divorced | 8.12 | 6.41 | 10.02 | 12.49 |
Widowed | 8.22 | 2.29 | 8.71 | 32.54 |
Education | ||||
No formal schooling | 3.57 | 1.26 | 3.58 | 13.02 |
Less than primary school | 5.39 | 3.20 | 4.37 | 15.84 |
Primary school completed | 16.42 | 14.79 | 14.95 | |
Secondary school completed | 35.69 | |||
High school (or equivalent) completed | 25.98 | 29.34 | 10.49 | |
College/pre-university/University completed | 11.16 | 8.79 | 18.59 | 10.03 |
Post graduate degree completed | 1.79 | 1.48 | 3.09 | 1.15 |
Current job | ||||
Government employee | 16.86 | 19.10 | 18.33 | 4.74 |
No government employee | 28.72 | 6.90 | ||
Self-employed | 26.09 | 29.74 | 23.14 | 14.54 |
Employer | 1.89 | 2.03 | 2.27 | 0.70 |
Homemaker | 8.28 | 6.88 | 10.70 | 10.75 |
Looked but can't find a job | 3.87 | 3.37 | 4.28 | 5.40 |
Studies | 2.11 | 2.58 | 2.13 | 0.04 |
Retired | 9.54 | 1.70 | 7.98 | |
Other | 2.63 | 1.11 | 1.92 | 10.44 |
Health Status | ||||
Very Good | 18.30 | 32.30 | 0.00 | 0.00 |
Good | 45.65 | 29.56 | 0.00 | |
Moderate | 29.08 | 0.00 | ||
Bad | 5.96 | 0.00 | 0.00 | 31.92 |
Very Bad | 1.00 | 0.00 | 0.00 | 5.38 |
Difficulty moving around | ||||
None | 76.48 | 45.38 | 0.00 | |
Mild | 12.79 | 0.00 | 0.00 | |
Moderate | 7.00 | 0.00 | 0.00 | |
Severe | 3.13 | 0.00 | 0.00 | 29.18 |
Extreme/Cannot do | 0.59 | 0.00 | 0.00 | 5.53 |
Difficulty in Self-Care | ||||
None | 90.45 | |||
Mild | 5.58 | 0.00 | 11.89 | 23.66 |
Moderate | 2.64 | 0.00 | 0.00 | 21.63 |
Severe | 1.01 | 0.00 | 0.00 | 8.26 |
Extreme/Cannot do | 0.33 | 0.00 | 0.00 | 2.70 |
Pain and discomfort | ||||
None | 53.18 | 0.00 | 0.00 | |
Mild | 24.39 | 0.00 | 0.00 | |
Moderate | 14.94 | 0.00 | 0.00 | |
Severe | 6.34 | 0.00 | 0.00 | 28.26 |
Extreme | 1.16 | 0.00 | 0.00 | 5.16 |
Difficulty in concentration | ||||
None | 69.28 | 0.00 | 0.00 | |
Mild | 18.84 | 0.00 | 0.00 | |
Moderate | 8.09 | 0.00 | 0.00 | |
Severe | 3.26 | 0.00 | 0.00 | 27.49 |
Extreme/Cannot do | 0.52 | 0.00 | 0.00 | 4.37 |
Difficulty in personal relationships | ||||
None | 84.12 | |||
Mild | 10.57 | 0.00 | 42.43 | 11.10 |
Moderate | 3.81 | 0.00 | 0.00 | 27.54 |
Severe | 1.14 | 0.00 | 0.00 | 8.24 |
Extreme/Cannot do | 0.36 | 0.00 | 0.00 | 2.62 |
Difficulty in seeing and recognizing persons | ||||
None | 79.70 | 29.94 | ||
Mild | 11.23 | 0.00 | 43.10 | 8.31 |
Moderate | 5.58 | 0.00 | 0.00 | |
Severe | 2.68 | 0.00 | 0.00 | 18.24 |
Extreme/Cannot do | 0.81 | 0.00 | 0.00 | 5.54 |
Sleeping disorders | ||||
None | 65.62 | 0.00 | 0.00 | |
Mild | 18.80 | 0.00 | 0.00 | |
Moderate | 9.58 | 0.00 | 0.00 | |
Severe | 5.06 | 0.00 | 0.00 | 32.45 |
Extreme | 0.95 | 0.00 | 0.00 | 6.07 |
Feeling sad or depressed | ||||
None | 61.80 | 0.00 | 0.00 | |
Mild | 22.38 | 0.00 | 0.00 | |
Moderate | 10.25 | 0.00 | 0.00 | |
Severe | 4.53 | 0.00 | 0.00 | 28.64 |
Extreme | 1.04 | 0.00 | 0.00 | 6.56 |
Diagnosis of Arthritis | ||||
No | 91.38 | 47.36 | ||
Yes | 8.62 | 0.00 | 0.00 | |
Diagnosis of Angina Pectoris | ||||
No | 93.98 | |||
Yes | 6.02 | 0.00 | 0.00 | 39.53 |
Diagnosis of Asthma | ||||
No | 95.06 | |||
Yes | 4.94 | 1.75 | 6.01 | 16.43 |
Diagnosis of Depression | ||||
No | 94.10 | |||
Yes | 5.90 | 0.00 | 0.00 | 36.25 |
Individuals in pure type II were mainly female (60%), reported moderate health status (70.4%) and had some difficulty with physical and mental activities, especially moving around (54.6%), pain and discomfort (100%), concentration (100%), sleeping (100%), feeling sad or depressed (100%).
Respondents in pure type III were mainly female (76.3%), old (55.3%), married or cohabiting (47.9%), intermediate or lower education levels (24.2% and 25.3%, respectively), and retired (46.5%). They reported moderate health status (62.7%) and had more difficulty with physical and mental activities, especially moving around (65.3%), pain and discomfort (66.6%), concentration (68.1%), sleeping (61.5%), feeling sad or depressed (64.8%) and had arthritis (52.6%).
GoM range |
I | II | III | |||
% | % | % | ||||
0 | 6601 | 11.23 | 22813 | 38.80 | 25817 | 43.91 |
0.01–0.25 | 4434 | 7.54 | 13307 | 22.63 | 11469 | 19.51 |
0.26–0.50 | 10227 | 17.39 | 15642 | 26.60 | 10894 | 18.53 |
0.51–0.75 | 12412 | 21.11 | 5355 | 9.11 | 6080 | 10.34 |
0.76–0.99 | 13841 | 23.54 | 1421 | 2.42 | 3065 | 5.21 |
1 | 11284 | 19.19 | 261 | 0.44 | 1474 | 2.51 |
Age-standardized prevalence (%) |
GoM scores range from 0 (no membership in that health profile) to 1 (exclusive membership in that health profile).
Freq (%) | I | II | III | |
Sex | ||||
Female | 55.66 | 46.29 | ||
Male | 44.34 | 33.13 | 29.65 | |
Age | ||||
Young Adult (18–29) | 28.38 | 39.72 | 15.64 | 8.71 |
Adult (30–59) | 55.70 | |||
Old Adult (60+) | 15.92 | 3.86 | 22.18 | 43.73 |
Marital status | ||||
Never Married | 22.18 | 30.44 | 10.27 | 10.76 |
Currently married/Cohabiting | 64.85 | |||
Separated/Divorced | 4.73 | 3.53 | 5.94 | 6.89 |
Widowed | 8.24 | 1.84 | 10.22 | 23.89 |
Education | ||||
No formal schooling | 15.66 | 10.36 | 10.66 | |
Less than primary school | 16.76 | 15.32 | 15.54 | 21.70 |
Primary school completed | 25.29 | 21.75 | ||
Secondary school completed | 19.99 | 22.53 | 23.52 | 10.01 |
High school (or equivalent) completed | 11.90 | 14.00 | 11.03 | 7.13 |
College/pre-university/University completed | 9.63 | 10.34 | 12.70 | 4.89 |
Post graduate degree completed | 0.76 | 1.15 | 0.34 | 0.13 |
Current job | ||||
Government employee | 8.42 | 9.93 | 9.75 | 2.90 |
No government employee | 15.29 | 20.39 | 10.05 | 5.94 |
Self-employed | 25.25 | 25.84 | 19.59 | |
Employer | 1.50 | 1.29 | 2.27 | 1.35 |
Homemaker | 25.10 | 21.68 | ||
Looked but can't find a job | 8.04 | 10.19 | 4.08 | 5.79 |
Studies | 4.10 | 5.28 | 0.89 | 3.85 |
Retired | 7.74 | 1.46 | 12.19 | 21.13 |
Other | 4.56 | 2.71 | 3.38 | 10.87 |
Health Status | ||||
Very Good | 18.99 | 38.29 | 0.00 | 0.00 |
Good | 37.99 | 28.75 | 0.00 | |
Moderate | 32.28 | 0.00 | ||
Bad | 8.91 | 0.00 | 0.00 | 36.00 |
Very Bad | 1.83 | 0.00 | 0.00 | 7.38 |
Difficulty moving around | ||||
None | 67.66 | 0.00 | 0.00 | |
Mild | 13.55 | 0.00 | 0.00 | |
Moderate | 13.18 | 0.00 | 0.00 | |
Severe | 4.87 | 0.00 | 0.00 | 25.91 |
Extreme/Cannot do | 0.74 | 0.00 | 0.00 | 3.96 |
Difficulty in Self-Care | ||||
None | 83.02 | 31.52 | ||
Mild | 7.96 | 0.00 | 28.16 | 15.99 |
Moderate | 6.60 | 0.00 | 0.00 | |
Severe | 1.92 | 0.00 | 0.00 | 11.16 |
Extreme/Cannot do | 0.51 | 0.00 | 0.00 | 2.94 |
Pain and discomfort | ||||
None | 46.79 | 0.00 | 0.00 | |
Mild | 23.88 | 0.00 | 0.00 | |
Moderate | 18.19 | 0.00 | 0.00 | |
Severe | 9.78 | 0.00 | 0.00 | 33.33 |
Extreme | 1.37 | 0.00 | 0.00 | 4.67 |
Difficulty in concentration | ||||
None | 60.63 | 0.00 | 0.00 | |
Mild | 19.08 | 0.00 | 0.00 | |
Moderate | 13.81 | 0.00 | 0.00 | |
Severe | 5.64 | 0.00 | 0.00 | 27.78 |
Extreme/Cannot do | 0.85 | 0.00 | 0.00 | 4.17 |
Difficulty in personal relationships | ||||
None | 77.71 | 43.30 | 42.94 | |
Mild | 10.67 | 0.00 | 0.00 | |
Moderate | 8.08 | 0.00 | 0.00 | |
Severe | 1.82 | 0.00 | 0.00 | 9.90 |
Extreme/Cannot do | 1.72 | 1.80 | 0.00 | 3.23 |
Difficulty in seeing and recognizing persons | ||||
None | 74.54 | 44.44 | 28.58 | |
Mild | 11.01 | 0.00 | 0.00 | |
Moderate | 8.62 | 0.00 | 0.00 | |
Severe | 4.71 | 0.00 | 0.00 | 23.25 |
Extreme/Cannot do | 1.13 | 0.00 | 0.00 | 5.56 |
Sleeping disorders | ||||
None | 60.03 | 0.00 | 0.00 | |
Mild | 18.41 | 0.00 | 0.00 | |
Moderate | 13.77 | 0.00 | 0.00 | |
Severe | 6.90 | 0.00 | 0.00 | 32.02 |
Extreme | 0.89 | 0.00 | 0.00 | 4.13 |
Feeling sad or depressed | ||||
None | 56.46 | 0.00 | 0.00 | |
Mild | 21.22 | 0.00 | 0.00 | |
Moderate | 14.05 | 0.00 | 0.00 | |
Severe | 6.94 | 0.00 | 0.00 | 31.11 |
Extreme | 1.32 | 0.00 | 0.00 | 5.93 |
Diagnosis of Arthritis | ||||
No | 86.78 | |||
Yes | 13.22 | 0.00 | 18.42 | 42.89 |
Diagnosis of Angina Pectoris | ||||
No | 93.49 | |||
Yes | 6.51 | 0.00 | 0.00 | 29.01 |
Diagnosis of Asthma | ||||
No | 95.00 | |||
Yes | 5.00 | 1.96 | 5.13 | 13.16 |
Diagnosis of Depression | ||||
No | 95.07 | |||
Yes | 4.93 | 0.00 | 0.00 | 22.24 |
Individuals in pure type II were mainly female (66.9%), homemakers (31.5%), reporting moderate health status (71.2%) and with some difficulty with physical and mental activities, especially moving around (100%), pain and discomfort (100%), concentration (100%), personal relationships (56.7%), seeing and recognizing persons (55.6%), sleeping (100%), feeling sad or depressed (100%).
Finally, respondents in pure type III were mainly female (70.3%), adults (47.6%), married or cohabiting (58.5%), not educated (34.4%), and homemakers (28.6%). They reported moderate health status (56.6%) and had more difficulty with physical and mental activities, especially moving around (70.1%), pain and discomfort (62%), concentration (68%), personal relationships (43.9%), seeing and recognizing persons (42.6%), sleeping (63.8%), feeling sad or depressed (63%); but did not report any of the four conditions.
GoM range |
I | II | III | |||
% | % | % | ||||
0 | 9103 | 11.21 | 31132 | 38.33 | 39401 | 48.51 |
0.01–0.25 | 5793 | 7.13 | 17357 | 21.37 | 19195 | 23.63 |
0.26–0.50 | 13178 | 16.22 | 19777 | 24.35 | 11777 | 14.50 |
0.51–0.75 | 15885 | 19.56 | 9311 | 11.46 | 6144 | 7.56 |
0.76–0.99 | 19246 | 23.69 | 2766 | 3.41 | 2943 | 3.62 |
1 | 18020 | 22.19 | 882 | 1.09 | 1765 | 2.17 |
Age-standardized prevalence (%) |
GoM scores range from 0 (no membership in that health profile) to 1 (exclusive membership in that health profile).
Freq (%) | I | II | III | |
Sex | ||||
Female | 53.28 | 46.63 | ||
Male | 46.72 | 39.86 | 32.53 | |
Age | ||||
Young Adult (18–29) | 34.79 | 19.32 | 8.54 | |
Adult (30–59) | 53.03 | |||
Old Adult (60+) | 12.19 | 2.43 | 17.51 | 39.92 |
Marital status | ||||
Never Married | 16.33 | 23.31 | 8.00 | 2.85 |
Currently married/Cohabiting | 71.06 | |||
Separated/Divorced | 4.25 | 3.46 | 4.51 | 6.67 |
Widowed | 8.35 | 2.49 | 10.86 | 25.30 |
Education | ||||
No formal schooling | 41.55 | |||
Less than primary school | 17.06 | 16.93 | 18.44 | 15.80 |
Primary school completed | 20.46 | 24.89 | 14.73 | 12.11 |
Secondary school completed | 11.53 | 15.07 | 7.86 | 3.75 |
High school (or equivalent) completed | 4.93 | 6.77 | 2.69 | 1.29 |
College/pre-university/University completed | 3.70 | 5.17 | 1.91 | 0.82 |
Post graduate degree completed | 0.76 | 0.96 | 0.49 | 0.40 |
Current job | ||||
Government employee | 4.36 | 5.73 | 2.90 | 1.35 |
No government employee | 6.77 | 8.71 | 4.13 | 3.23 |
Self-employed | 48.97 | |||
Employer | 0.93 | 0.86 | 1.19 | 0.83 |
Homemaker | 22.77 | 18.96 | 29.74 | 27.38 |
Looked but can't find a job | 4.23 | 5.52 | 1.80 | 2.76 |
Studies | 3.45 | 5.15 | 1.16 | 0.33 |
Retired | 4.68 | 0.68 | 5.74 | 17.60 |
Other | 3.84 | 2.25 | 2.57 | 11.17 |
Health Status | ||||
Very Good | 26.29 | 47.86 | 0.00 | 0.00 |
Good | 39.75 | 43.27 | 0.00 | |
Moderate | 25.58 | 0.00 | ||
Bad | 7.36 | 0.00 | 0.00 | 37.94 |
Very Bad | 1.02 | 0.00 | 0.00 | 5.25 |
Difficulty moving around | ||||
None | 67.34 | 0.00 | 0.00 | |
Mild | 16.80 | 0.00 | 0.00 | |
Moderate | 9.59 | 0.00 | 0.00 | |
Severe | 5.35 | 0.00 | 0.00 | 33.73 |
Extreme/Cannot do | 0.92 | 0.00 | 0.00 | 5.81 |
Difficulty in Self-Care | ||||
None | 79.73 | 0.00 | ||
Mild | 11.70 | 0.00 | 41.02 | 26.54 |
Moderate | 5.42 | 0.00 | 0.00 | |
Severe | 2.45 | 0.00 | 0.00 | 20.99 |
Extreme/Cannot do | 0.70 | 0.00 | 0.00 | 5.96 |
Pain and discomfort | ||||
None | 48.54 | 0.00 | 0.00 | |
Mild | 26.93 | 0.00 | 0.00 | |
Moderate | 14.68 | 0.00 | 0.00 | |
Severe | 8.56 | 0.00 | 0.00 | 34.90 |
Extreme | 1.29 | 0.00 | 0.00 | 5.25 |
Difficulty in concentration | ||||
None | 63.22 | 0.00 | 0.00 | |
Mild | 20.64 | 0.00 | 0.00 | |
Moderate | 10.32 | 0.00 | 0.00 | |
Severe | 4.98 | 0.00 | 0.00 | 30.82 |
Extreme/Cannot do | 0.85 | 0.00 | 0.00 | 5.24 |
Difficulty in personal relationships | ||||
None | 77.89 | 45.99 | 28.32 | |
Mild | 13.01 | 0.00 | 11.46 | |
Moderate | 5.59 | 0.00 | 0.00 | |
Severe | 2.52 | 0.00 | 0.00 | 16.67 |
Extreme/Cannot do | 0.99 | 0.00 | 0.00 | 6.55 |
Difficulty in seeing and recognizing persons | ||||
None | 78.08 | 29.70 | ||
Mild | 10.46 | 0.00 | 48.46 | 0.00 |
Moderate | 6.38 | 0.00 | 0.00 | |
Severe | 3.90 | 0.00 | 0.00 | 23.91 |
Extreme/Cannot do | 1.19 | 0.00 | 0.00 | 7.27 |
Sleeping disorders | ||||
None | 63.53 | 0.00 | 0.00 | |
Mild | 19.09 | 0.00 | 0.00 | |
Moderate | 10.31 | 0.00 | 0.00 | |
Severe | 5.98 | 0.00 | 0.00 | 34.45 |
Extreme | 1.08 | 0.00 | 0.00 | 6.20 |
Feeling sad or depressed | ||||
None | 56.87 | 0.00 | 0.00 | |
Mild | 23.16 | 0.00 | 0.00 | |
Moderate | 11.49 | 0.00 | 0.00 | |
Severe | 7.05 | 0.00 | 0.00 | 35.29 |
Extreme | 1.44 | 0.00 | 0.00 | 7.19 |
Diagnosis of Arthritis | ||||
No | 85.40 | 48.20 | ||
Yes | 14.60 | 0.00 | 20.89 | |
Diagnosis of Angina Pectoris | ||||
No | 92.56 | |||
Yes | 7.44 | 0.00 | 6.19 | 32.16 |
Diagnosis of Asthma | ||||
No | 95.85 | |||
Yes | 4.15 | 0.00 | 4.80 | 17.05 |
Diagnosis of Depression | ||||
No | 93.69 | |||
Yes | 6.31 | 0.00 | 0.00 | 32.26 |
Respondents in pure type II were mainly female (60.1%), reported moderate health status (56.7%) and had some difficulty with physical and mental activities, especially moving around (100%), pain and discomfort (100%), concentration (100%), personal relationships (54%), sleeping (100%), feeling sad or depressed (100%).
Finally, respondents in pure type III were mainly female (64.5%), adults (51.5%), married or cohabiting (65.2%), not educated (65.8%), and self-employed (35.3%). They had moderate health status (56.8%), more difficulty with physical and mental activities, especially moving around (60.4%), self-care (46.5%), pain and discomfort (59.8%), concentration (63.9%), sleeping (59.3%), feeling sad or depressed (57.5%), and arthritis (51.8%).
Age-standardized prevalence ratios of pure type I by economic category indicate similarity between the high and upper-middle income countries (both over 62%) and the lower-middle and low income countries (both less than 59%). Likewise, the two higher income categories had less than 16% membership in the FRAIL pure type whilst the lower-middle and low income countries had higher rates (21.8% and 19.2%, respectively).
This paper described the application of the Grade of Membership models to summarize population health status using World Health Survey data. The GoM model provided a meaningful method to reduce and summarize health variables from health surveys.
A number of techniques have previously been applied to WHS data to summarize and report on health status
The GoM procedure differs from other classification methods, like Factor Analysis, which use indicators to calculate latent continuous variables that represent one-dimensional constructs. Factor Analysis results derive the parameter values from normally distributed data, whereas, the GoM model is a non-parametric method where identification of parameters does not rely on any distributional assumptions. Estimation of factor scores in Factor Analysis supports on distributional assumptions relating to the factor loadings
Grade of Membership modelling shares similarities with other data reduction methods, such as Factor Analysis, Principal Component Analysis and Cluster Analysis. However, in the GoM model, all parameters are simultaneously identified, while, individual parameters in Factor Analysis and Principal Components methods are usually calculated using summary variables derived from within the dataset
Additionally, in contrast to the Factor Analysis and Principal Component methods, GoM is a classification methodology where respondents are allocated to discrete and meaningful groups based on their grade of membership profile. Unlike other classification methodologies (such as Cluster Analysis), GoM does not generate groups of similar entities but considers individual heterogeneity
Grade of Membership analysis has been previously used to summarize health data from surveys for depressive symptoms and personality disorders, older people health status and genetic studies of health. Woodbury et al.
In this study, the GOM model produced three pure types (health profiles) for each economic category. Each health profile described unique facets of physical and mental health (internal GoM model variables) plus differences in socio-demographic characteristics (external GoM model variables) with a clear economic gradient (lower education and employment sector) when moving from high to low economic categories within each profile. Type I (ROBUST) and Type II (INTERMEDIATE) health profiles were more similar in both external and internal variables, as well as World Bank economic category, when compared to the Type III (FRAIL) profile.
The
The
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All four economic categories had somewhat similar robust and intermediate health profiles (pure types I and II). The two higher economic categories had more respondents in the robust pure type (greater than 64%) than the lower economic categories (less than 59%). Likewise, the two lower economic categories had more respondents in the frail pure types, (21.8% and 19.2%, respectively), with similar rates of membership in the intermediate profile across all four economic categories. The frail profile types may provide a logical focus for attention at all levels of country wealth, with policies targeted, for example, at older widowed women with mobility, sleep and cognition problems.
These analyses have provided a robust method to better understand health status and the components which can help to identify healthy and non-healthy individuals. Three profiles,
In future, we plan to investigate the transitions between health profiles, both improving and declining health, as well as the impact of the health-wealth relationship on shifts between profiles. We will additionally, look at the use of frailty definitions and profiles across different settings and the impact on disability assessments. These will provide the basis to inform policy about aging populations and measures to redress the determinants of more vulnerable health profiles. With a view to make results more cross-nationally comparable, vignette adjustments would improve ability to differentiate and correct for any reporting bias across countries and categories. This adjustment would also likely show more dramatic differences in health for respondents in lower income countries.
Nirmala Naidoo and Ed Dowd kindly provided analytical assistance and intellectual guidance. Gene Lowrimore and Decision Systems, Inc., provided the DSIGoM software and support. Dennis Tolley and Paul Cannon provided advice and insights into newer GoM based techniques. The US National Institute of Ageing, Behavioural and Social Research Program supports the analytical and methodological work of WHO's Multi-Country Studies unit through an Inter-Agency Agreement.