Statistical methodology in oral and dental research: pitfalls and recommendations.

OBJECTIVES: This study describes the pitfalls for commonly used statistical techniques in dental research and gives some recommendations for avoiding them. It also explores the potential of some of the newer statistical techniques for dental research.
METHODS: Each of the commonly used techniques e.g. descriptive statistics, correlation and regression, hypothesis tests (parametric and non-parametric) and survival analysis are explored with examples and recommendations for their use are provided. Common sources of error including those of study design, insufficient information, ignoring the impact of clustering and underuse of confidence intervals are outlined. The potential of statistical techniques such as multivariate survival models, generalized estimating equations and multilevel models are also explored.
CONCLUSIONS: Reviews of published dental research repeatedly identify statistical errors in the design, analysis and conclusions of the study. Educating researchers on common pitfalls and giving recommendations for avoiding them may help researchers to eliminate statistical errors. Developments in statistical methodology should be routinely monitored to ensure the most appropriate statistical methods are used in dental research.