Table 1.

WMH sample characteristics by World Bank income categories^a

Country by income category	Surveyb	Sample characteristicsc	Field dates	Age range	Sample Size		Response rated
					Part 1	Part 2
I. Low and lower middle income countries
Iraq	IMHS	Nationally representative.	2006–7	18–96	4,332	4,332	95.2
TOTAL					(4,332)	(4,332)	95.2
II. Upper-middle income countries
Brazil - São Paulo	São Paulo Megacity	São Paulo metropolitan area.	2005–7	18–93	5,037	2,942	81.3
Colombia – Medellinf	MMHHS	Medellin metropolitan area	2011–12	19–65	3,261	1,673	97.2
Romania	RMHS	Nationally representative.	2005–6	18–96	2,357	2,357	70.9
TOTAL					(10,655)	(6,972)	82.8
III. High-income countries
Australiae	NSMHWB	Nationally representative.	2007	18–85	8,463	8,463	60
N. Ireland	NISHS	Nationally representative.	2004–7	18–97	4,340	1,986	68.4
Poland	EZOP	Nationally representative	2010–11	18–64	10,081	4,000	50.4
Portugal	NMHS	Nationally representative.	2008–9	18–81	3,849	2,060	57.3
Spain - Murcia	PEGASUS- Murcia		2010–12	18–64	2,621	1,459	67.4
IV. TOTAL					(29,354)	(17,968)	56.8
TOTAL					(44,341)	(29,272)	64.7

^aThe World Bank (2012) Data. Accessed May 12, 2012 at: http://data.worldbank.org/country. Some of the WMH countries have moved into new income categories since the surveys were conducted. The income groupings above reflect the status of each country at the time of data collection. The current income category of each country is available at the preceding URL.

^bIMHS (Iraq Mental Health Survey); MMHHS (Medellín Mental Health Household Study); RMHS (Romania Mental Health Survey); NSMHWB (National Survey of Mental Health and Wellbeing); NISHS (Northern Ireland Study of Health and Stress); EZOP (Epidemiology of Mental Disorders and Access to Care Survey); NMHS (Portugal National Mental Health Survey); PEGASUS-Murcia (Psychiatric Enquiry to General Population in Southeast Spain-Murcia).

^cMost WMH surveys are based on stratified multistage clustered area probability household samples in which samples of areas equivalent to counties or municipalities in the US were selected in the first stage followed by one or more subsequent stages of geographic sampling (e.g., 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. 6 of the 9 surveys are based on nationally representative household samples.

^dThe response rate is 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 of being 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 is 64.7%.

^eFor the purposes of cross-national comparisons we limit the sample to those 18+. The NSMHWB surveyed respondents aged 16–85 with a total sample size of 8841. The response rate reported here refers to the full survey sample response rate.

^fColombia moved from the “lower and lower-middle income” to the “upper-middle income” category between 2003 (when the Colombian National Study of Mental Health was conducted) and 2010 (when the Medellin Mental Health Household Study was conducted), hence Colombia’s appearance in both income categories. For more information, please see footnote a.