We did not exclude participants based on other criteria, such as recent trips to sunny destinations, use of certain medications, or medical conditions, all of which may have an effect on vitamin D metabolism.
Although we controlled for an array of covariates, including diet quality, some known routes of BPA and phthalate exposures, such as canned food or beverage consumption, contact with certain medical devices, and use of certain medications or consumer products (Buckley et al. 2012; Geens et al. 2012; Kelley et al. 2012), were not captured in our cohorts.
In adjusted analysis, we considered several confounders: age, race, sex, body mass index (BMI), menopausal status, tobacco use, alcohol use, physical activity, calcium intake, chronic medical conditions, use of certain medications, and socioeconomic status.
Nonetheless, it is important to note that the cognitive performance of patients may be influenced by factors not directly related to the presence of CHF, such as depression, anxiety, alcohol abuse, concomitant medical problems, and use of certain medications.
The main reasons for excluding a subject involve circumstances that make it unsafe for the subject to undergo an MRI, a PET scan, or a lumbar puncture, such as metal or shrapnel in the body, unstable medical conditions, or current use of certain medications.
As reported previously [ 16], medical history (presence of chronic diseases and use of certain medications), smoking habits (non-smokers, former or current smokers) and alcohol consumption (grams per week) were evaluated by the same questionnaire at baseline and follow-up that was developed by researchers at Lund University (Additional file 1).
This decline can also be attributed to a number of factors: age, genetics, nutrition, lifestyle factors, or the prolonged use of certain medication [ 3].
Environmental risk-factors, such as different obstacles and defect materials and remedies, also directly or indirectly cause falls [ 15, 16], and a significant correlation has been found between falls and the use of certain medication [ 17- 20].
In some settings 'deviant' registration tendencies have been identified whereby certain interventions that are routinely performed are not registered (e.g. artificial amniotomy, the use of certain medication to stimulate the normal process of labour) or no data are registered in a situation when no technical procedure/intervention has been performed [ 64].
Dr Doug Brown, from the UK's Alzheimer's Society, said: "There have been concerns that regular use by older people of certain medications with anticholinergic effects, such as sleep aids and hay-fever treatments, can increase the risk of dementia in certain circumstances, which this study supports.
More detailed information on the metabolic, cardiovascular and chronic kidney disease specific characteristics of HIVAN patients on dialysis, as well as the use and possible benefit of certain medications, especially ACE and antiretroviral drugs in this population, would supplement previous reports.
