Unique strengths of our present study include the availability of a well-comparable control group and of a wide range of information on lifestyle risk factors for TCB.
The main strengths of the present study include the availability of an unselected patient population (thus reducing the risk of selection and referral bias), the availability of clinical data which had been prospectively collected during routine clinical work independently of the study hypothesis, and the complete follow-up.
The strengths of the present study include the availability of information in several potential determinants of global DNA methylation and hydroxymethylation, including metals and arsenic metabolism and the high quality of standardized protocols for the recruitment of participants, conduction of interviews, physical examinations, collection of biological samples, and laboratory analysis.
Unique features of the present study include the availability of data on arsenic exposure measured in both urine and water, the use of repeat measurements of total urinary arsenic to measure internal dose of arsenic exposure and to track changes in exposure levels over time, and the information on cigarette smoking.
Methodological strengths of the present study include the large sample size, the availability of comparable survey instruments, the sampling strategies and methods of data collection, and also, the diverse nature of the various oral health-related behaviors.
Strengths of the present study include the large sample size, the prolonged duration of the study, the availability of information to allow some classification of subtypes of preterm birth, and the availability of some covariate data to allow multivariate analysis; however, some important information was missing.
Other strengths of the present study include the central adjudication of diagnoses of colorectal cancer in WHI; the negligible loss to follow-up; and the availability of information on a wide range of potential confounding variables.
The key contributions of the present study include the following.
Limitations of the study include the availability of only pre-diagnostic information for NSAIDs and HT.
Advantages of this study include the availability of hourly data on PM2.5 and PM2.5 chemical composition.
