Maximum variability sampling was used so therefore every effort was made by the researcher to obtain a sample of the intended end-users of the toolkit [ 31].
Snowball and maximum variability sampling techniques were used, the former of which is a practical means of building a respondent base, and the latter of which aims for heterogeneity in the sample.
24 25 26 This was achieved by drawing up a list of hospitals planning to implement different functionality during the course of our evaluation and using maximum variability sampling to identify sites to approach.
To provide as much data as possible to inform the design of the consultation aid, a maximum variability sample for both the patients and the doctors was required.
Although we opted for a maximum variability sample in terms of location of postholder (geographical spread, urban/regional, based in acute services or community practice), case selection was ultimately limited to the availability of a matched service without a postholder for comparison.
Selection was done by their main mental health care provider (psychiatrist) taking into consideration the maximum variability of sampling in gender, work status, and clinical status (totally remitted, partially remitted, and nonremitted), consulting the patients' clinical records.
During the selection process, the psychiatrists who were responsible for the recruitment of participants took into consideration the maximum variability of sampling, but the time frame and the profile of patients in the catchment area of the Hospital Universitario de la Princesa in general did not allow us to have a more representative sample in terms of age.
However, use of Primer 6 software to generate multidimensional scaling plots of maximum variability among samples revealed a seasonal trend in the data set (Fig. S4), similar to results shown in Fig. 4, with April and August samples clustering separately.
Newly diagnosed and follow-up patients were recruited to ensure maximum variability in our sample group.
As such, we used a purposive sampling approach for maximum variability for the observational study and a sample of convenience for the questionnaire study.
Unlike previous studies, this study focused on health care, included all countries in the initial search (as opposed to only India or Africa), and looked for patterns across a series of cases sampled for maximum variability.
