Background: Shoulder arthroplasty has been shown to improve function in patients with advanced shoulder disease. However, the response to surgery and final outcomes are not easily predictable. This study assessed the effect of residual pain, age, sex, diabetes, hypertension, and depression on changes and status at one-year following arthroplasty with respect to shoulder function and overall physical and mental health status. Methods: A retrospective analysis of a prospective cohort of 140 patients tested preoperatively and one-year following shoulder arthroplasty was conducted at our tertiary hospital. Pearson's correlations and multiple regression analysis were performed to test the impact of predictors on shoulder pain and function assessed using the American Shoulder and Elbow Surgery (ASES) questionnaire, and on physical and mental health assessed using the Short Form-12. Results: Pain and female sex were significant predictors of poorer function at one-year (R = .56, p = .001); and with other predictors, they explained 32% of the variability in function. The explained variability of changes in function scores was 15% with pain being the only significant predictor. Physical health was lower in older patients (r = -.31, p < .05) and was less predictable for physical health change scores (12%) and the physical status at one-year (14%). Conclusions: Residual pain is associated with poorer function status and less clinical benefits. Female sex is not associated with less change in function which suggests that men and women get equal benefit from the surgery. Advanced age relates to poorer physical health and to a lesser extent physical change over the year.Level of Evidence: III.