Seaweed consumption was calculated using semiquantitative frequency questions regarding two separate food items: Wakame or Hijiki and Nori.
Although the stability of sample and term configurations from CATA and RATA questions, calculated using a bootstrapping re-sampling approach, were similar, for two of the four studies RATA questions provided more stable sample and term configurations.
For each type of research use, the internal reliability coefficient of the corresponding questions was calculated, using Cronbach's Alpha [ 23].
Health-related utilities and in consequence quality-adjusted life-years (QALYs) were measured using the SF-6D, which is calculated using a sub-set of questions from the SF-12[ 39].
Pack-years of smoking were calculated using answers to 12 tobacco questions and included assessment of current number of cigarettes smoked, maximum number of cigarettes smoked, and periods during which a current smoker did not smoke.
The Physical and Mental Component Summary (PCS and MCS) norm-based scores for the SF-12 were calculated using the reversed scores of questions 1, 8, 9 and 10 [ 22].
To address these questions, we calculated, using mathematical modelling, the population log10 viral load in a representative nation in SSA, Tanzania, to examine population viral load variation from the start of the epidemic up to today, and its future evolution with ART scale-up.
The elements are rotated factor loadings (columns 2 3), communalities (column 4), Cronbach's alpha coefficient with the item in question deleted, calculated using standardized variables (column 5), and the item-total correlation, calculated using standardized variables (column 6).
Percentage scores for each question were calculated using the scoring rubric outlined in Additional file 2. The three domains, (i) government engagement, (ii) partner and civil society engagement, and (iii) data generation, were also aggregated to form an index score, the HIV M&E System Capacity Index (MESCI) (see Additional file 2 for individual components and scoring calculations).
This was defined as RE = reported presence of orangutans in the last year/potential of encountering an orangutan, where potential of encountering an orangutan was calculated using a combination of responses to questions involving the number of trips to forest per year, reason for travel to forest and number of nights spent in the forest on each trip.
