title: Brief Report: Assessing and Interpreting the Association Between Continuous Covariates and Outcomes in Observational Studies of HIV Using Splines.
abstract: The HIV epidemiology literature is replete with studies that categorize continuous predictors, such as age and CD4 cell count. It is well known that such an approach is suboptimal, but it persists in part because results are easy to interpret after categorization. Splines may be used to incorporate continuous predictors with smoothed curves into regression models without categorization or linearity assumptions. Properly presenting and interpreting results from analyses with splines is critical for their widespread use. With data from 13,706 antiretroviral initiators in Latin America, we demonstrate how to interpret results from a Cox regression model using restricted cubic splines.
authors: Departments of *Biostatistics; and †Medicine, Vanderbilt University School of Medicine, Nashville, TN.
authors: Bryan E
authors: BE
authors: Shepherd
authors: Peter F
authors: PF
authors: Rebeiro
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D056808:Biostatistics / Q000379:methods*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000401:mortality*; D006801:Humans; D007843:Latin America / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D064887:Observational Studies as Topic; D011379:Prognosis; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents