Additional analyses considering body mass index (BMI) were restricted to a sample of 158 936 due to missing and/or implausible values for height and/or weight.
To our knowledge, only Lee and colleagues [ 19] have examined serum prolactin levels in conjunction with PRL and PRLR genotypes and breast cancer risk, but examination of serum prolactin levels was restricted to a sample of postmenopausal women only.
Lastly, our findings are restricted to a small sample of women residing within an area of South Wales who opted to take part within our study.
Since it was not possible to obtain the information on a number of these variables for all patients (e.g. employment status was only requested in the interview and therefore not available for people who died before being interviewed), most of the stratified analyses are restricted to a limited sample size ranging between 89.9 % (diabetes) and 53.3 % (smoking) of the total population.
If the problems, ranging from programming errors and voter errors to fraud, are restricted to a few precincts, such sampling would rarely detect it.
Since there are a total of 14 and 21 variants in categories 2B and 3B respectively, most of these cases are restricted to a single individual in the sample of 12. Details for these predicted deleterious variants are listed in Additional file 2: Tables S5, S6, respectively.
Our sample was restricted to a homogeneous sample of Mexican children with a lower prevalence of the C282Y variant (heterozygotes, 3.3%) than people from Europe (9.2%) and the Americas (9.0%), but a higher prevalence than people from Africa/Middle East (0.2%), the Indian subcontinent (0.5%), Asia (0%), and Australia (0%) (Hanson et al. 2001).
After sample size calculation the cohort was restricted to a representative sample of 34,393 migrants according to the spatial distribution and urban/rural proportion who were at least 15 years old when they migrated to Germany.
Because of space limitations, the reference list has been restricted to a select sample from the past five years.
Finally, our observations were restricted to a small sample of patients in septic shock.
The presence in VSCC of both integrated and episomal forms has been shown (Ueda et al, 2004), although analysis was restricted to a single sample.
