Table 1.
World Mental Health (WMH) Survey sample characteristics
| Sample size | ||||||||
|---|---|---|---|---|---|---|---|---|
| Country | Surveya | Sample characteristicsb | Field dates | Age range | Part I | Part II | Part II and age ≤ 44 yearsd | Response ratec |
| I. High-income | ||||||||
| Belgium | ESEMeD | Stratified multistage clustered probability sample of individuals residing in households from the national register of Belgium residents. NR | 2001-2 | 18+ | 2419 | 1043 | 486 | 50.6 |
| France | ESEMeD | Stratified multistage clustered sample of working telephone numbers merged with a reverse directory (for listed numbers). Initial recruitment was by telephone, with supplemental in-person recruitment in households with listed numbers. NR | 2001-2 | 18+ | 2894 | 1436 | 727 | 45.9 |
| Germany | ESEMeD | Stratified multistage clustered probability sample of individuals from community resident registries. NR | 2002-3 | 18+ | 3555 | 1323 | 621 | 57.8 |
| Israel | NHS | Stratified multistage clustered area probability sample of individuals from a national resident register. NR | 2002-4 | 21+ | 4859 | 4859 | -- | 72.6 |
| Italy | ESEMeD | Stratified multistage clustered probability sample of individuals from municipality resident registries. NR | 2001-2 | 18+ | 4712 | 1779 | 853 | 71.3 |
| Japan | WMHJ 2002-2006 | Unclustered two-stage probability sample of individuals residing in households in nine metropolitan areas (Fukiage, Higashi-ichiki, Ichiki, Kushikino, Nagasaki, Okayama, Sano, Tamano, Tendo Tochigi) | 2002-6 | 20+ | 3416 | 1305 | 425 | 59.2 |
| Netherlands | ESEMeD | Stratified multistage clustered probability sample of individuals residing in households that are listed in municipal postal registries. NR | 2002-3 | 18+ | 2372 | 1094 | 516 | 56.4 |
| New Zealande | NZMHS | Stratified multistage clustered area probability sample of household residents. NR | 2004-5 | 18+ | 12790 | 7312 | 4119 | 73.3 |
| Spain | ESEMeD | Stratified multistage clustered area probability sample of household residents. NR | 2001-2 | 18+ | 5473 | 2121 | 960 | 78.6 |
| United States | NCS-R | Stratified multistage clustered area probability sample of household residents. NR | 2002-3 | 18+ | 9282 | 5692 | 3197 | 70.9 |
| II. Low- to middle-income | ||||||||
| Brazil | São Paulo megacity | Stratified multistage clustered area probability sample of household residents in the São Paulo metropolitan area, Brazil | 2004-7 | 18+ | 5037 | 2942 | -- | 77.7 |
| Colombia | NSMH | Stratified multistage clustered area probability sample of household residents in all urban areas of the country (approximately 73% of the total national population) | 2003 | 18-65 | 4426 | 2381 | 1731 | 87.7 |
| India | WMHI | Stratified multistage clustered area probability sample of household residents in Pondicherry region, India. NR | 2003-5 | 18+ | 2992 | 1373 | 642 | 98.6 |
| Lebanon | LEBANON | Stratified multistage clustered area probability sample of household residents. NR | 2002-3 | 18+ | 2857 | 1031 | 595 | 70.0 |
| Mexico | M-NCS | Stratified multistage clustered area probability sample of household residents in all urban areas of the country (approximately 75% of the total national population) | 2001-2 | 18-65 | 5782 | 2362 | 1736 | 76.6 |
| South Africa | SASH | Stratified multistage clustered area probability sample of household residents. NR | 2003-4 | 18+ | 4315 | 4315 | -- | 87.1 |
| Ukraine | CMDPSD | Stratified multistage clustered area probability sample of household residents. NR | 2002 | 18+ | 4724 | 1719 | 540 | 78.3 |
| PRC | Shenzhen | Stratified multistage clustered area probability sample of household residents and temporary residents in the Shenzhen area, China | 2006-7 | 18+ | 7132 | 2475 | 1994 | 80.0 |
aESEMeD (The European Study Of The Epidemiology Of Mental Disorders); NHS (Israel National Health Survey); WMHJ 2002-2006 (World Mental Health Japan Survey); NZMHS (New Zealand Mental Health Survey); NCS-R (The USA National Comorbidity Survey Replication); NSMH (The Colombian National Study of Mental Health); WMHI (World Mental Health India); LEBANON (Lebanese Evaluation of the Burden of Ailments and Needs of the Nation); M-NCS (The Mexico National Comorbidity Survey); SASH (South Africa Stress and Health Study); CMDPSD (Comorbid Mental Disorders during Periods of Social Disruption)
bMost WMH surveys are based on stratified multistage clustered area probability household samples in which samples of areas equivalent to counties or municipalities in the USA were selected in the first stage, followed by one or more subsequent stages of geographic sampling (for example,, towns within counties, blocks within towns, households within blocks) to arrive at a sample of households, in each of which a listing of household members was created, and one or two people were selected from this listing to be interviewed. No substitution was allowed when the originally sampled household resident could not be interviewed. These household samples were selected from Census area data in all countries other than France (for which telephone directories were used to select households) and the Netherlands (for which postal registries were used to select households). Several WMH surveys (Belgium, Germany, Italy) used municipal resident registries to select respondents without listing households. The Japanese sample is the only totally unclustered sample, with households randomly selected in each of the four sample areas, and one random respondent selected in each sample household. Fourteen surveys are based on nationally representative (NR) household samples, and two others (Colombia, Mexico) were based on nationally representative household samples in urbanized areas. The Israeli survey is a representative sample of individuals.
cThe response rate was calculated as the ratio of the number of households in which an interview was completed to the number of households originally sampled, excluding from the denominator households known not to be eligible either because they were vacant at the time of initial contact or because the residents were unable to speak the designated languages of the survey. The weighted average response rate for all countries included was 71.7%.
dBrazil, Israel and South Africa did not have an age-restricted part II sample. All other countries, with the exception of India and Ukraine (which were age-restricted to ≤ 39 years) were age-restricted to ≤ 44 tears.
eThe New Zealand response rate was calculated on the entire survey sample size which was of respondents age 16+ years, giving a total of 12,992. For purposes of this analysis we only used respondents aged 18+ years.