National Center for Health Statistics guidelines for analysis of trends

Background: Many reports present analyses of trends over time based on multiple years of data from National Center for Health Statistics (NCHS) surveys and the National Vital Statistics System (NVSS). Trend analyses of NCHS data involve analytic choices that can lead to different conclusions about the trends.Objective: This report discusses issues that should be considered when conducting a time trend analysis using NCHS data and presents guidelines for making trend analysis choices.Results: Trend analysis issues discussed include: choosing the observed time points to include in the analysis, considerations for survey data and vital records data (record level and aggregated), a general approach for conducting trend analyses, assorted other analytic issues, and joinpoint regression. This report provides12 guidelines for trend analyses, examples of analyses using NCHS survey and vital records data, statistical details for some analysis issues, and SAS and SUDAAN code for specification of joinpoint regression models.Conclusions: Several analytic choices must be made during the course of a trend analysis, and the choices made can affect the results. This report highlights the strengths and limitations of different choices and presents guidelines for making some of these choices. While this report focuses on time trend analyses, the issues discussed and guidelines presented are applicable to trend analyses involving other ordinal and interval variables.CS289898Acknowledgments -- Abstract -- Introduction -- Trend Analysis Issues and Guidelines: Choosing the Observed Time Points; Conducting Trend Analyses ; Other Analytic Issues and Guidelines; Joinpoint Regression -- Illustrative Examples of Trend Analysis -- Future Research -- Summary -- References -- Appendix I. Three Methods for Estimating Slope in Trend Analyses of Survey Data -- Appendix II. The E ect of Pooling Data Over Time on the Variance of a Slope Estimate -- Appendix III. Assessing Nonlinear Trends With Three Time Points -- Appendix IV. Joinpoint Regression: What it is and how to Parameterize a Model -- Appendix V. Calculating a Cochran-Mantel-Haenszel Test for Trend in SUDAAN -- Appendix VI. Transforming Proportions to Log Odds Scale.20189780840606891084060689