Methods
A full report of the methods employed within the NCS-R
can be found in Kessler et al. [26]: The NCS-R undertaken
by the World Mental Health team as “a nationally
representative community household survey of the
prevalence and correlates of mental disorders in the US”
[26]. Data was collected between February 2001 and
April 2003 [26]. Participants were selected from a nationally
representative multi stage clustered area probability
sample of households [26]. The study was subdivided
into two sections, with all respondents receiving part 1
(N = 9282), with reported sampling strategies and criteria
for selecting participants to receive part two (N = 5692)
[26]. However, over and above these criteria, to reduce
financial cost and participant burden, certain subsections
(including family burden) were only administered to a
30% subsample where it was deemed that the data analysis
goals could be achieved by administering the section
to a probability subsample of respondents [26].
The recruitment, consent and field procedures within
the NCS-R were approved by the Human Subjects Committees
of both the Harvard Medical School and the
University of Michigan [26]. The principles align with
those of the declaration of Helsinki for ethical principles
for medical research involving humans. Recruitment
protocol took the form of an advance letter and study
fact brochure, followed several days later by interviewer
contact [26]. Interviewers used a standardised method to
select a random respondent within each household, and
obtained verbal informed consent [26]. Respondents
were given a minimum $50 for participation [26]. If the
initially selected participant declined, the invitation was
extended to another person within the household [26].
The number of occasions on which this happened is not
reported [26]. Reports are not given on how many
households were contacted but then did not uptake participation
in the survey [26], however persuasion letters
were sent; and 60 days before the end of the closeout
period, a special effort was made by sending a letter
offering an increased financial incentive to complete an
abbreviated interview either in person orby telephone
[26]. It is however reported that interviews were only
broken off by 107 out of 9389 initial NSCR respondents,
and that the overall response rate was 74.6%, with 9282
completed interviews [26].
For methodological reasons, interviews were administered
face to face in the homes of respondents using
laptop assisted personal interview methods by professional
survey interviewers [26]. Minimum survey completion
time was 90 minutes (when no lifetime disorders
reported), with average completion time being 2 hours
30 minutes, and stretching to 6 hours where complex
history was present [26]. Interviewers gauged participant
fatigue and suggested breaks where necessary, with time