Purpose Persistent pain after breast cancer surgery is a well-recognized problem, with moderate to severe pain affecting 15% to 20% of women at 1 year from surgery. Several risk factors for persistent pain have been recognized, but tools to identify high-risk patients and preventive interventions are missing. The aim was to develop a clinically applicable risk prediction tool. Methods The prediction models were developed and tested using three prospective data sets from Finland (n = 860), Denmark (n = 453), and Scotland (n = 231). Prediction models for persistent pain of moderate to severe intensity at 1 year postoperatively were developed by logistic regression analyses in the Finnish patient cohort. The models were tested in two independent cohorts from Denmark and Scotland by assessing the areas under the receiver operating characteristics curves (ROC-AUCs). The outcome variable was moderate to severe persistent pain at 1 year from surgery in the Finnish and Danish cohorts and at 9 months in the Scottish cohort. Results Moderate to severe persistent pain occurred in 13.5%, 13.9%, and 20.3% of the patients in the three studies, respectively. Preoperative pain in the operative area ( P < .001), high body mass index ( P = .039), axillary lymph node dissection ( P = .008), and more severe acute postoperative pain intensity at the seventh postoperative day ( P = .003) predicted persistent pain in the final prediction model, which performed well in the Danish (ROC-AUC, 0.739) and Scottish (ROC-AUC, 0.740) cohorts. At the 20% risk level, the model had 32.8% and 47.4% sensitivity and 94.4% and 82.4% specificity in the Danish and Scottish cohorts, respectively. Conclusion Our validated prediction models and an online risk calculator provide clinicians and researchers with a simple tool to screen for patients at high risk of developing persistent pain after breast cancer surgery.

We studied postoperative pain trajectories and associated factors. Expectation of severe postoperative pain was associated with higher intensity of experimental and postoperative pain.

Background Sleep deprivation is often claimed to be increasingly common, but most studies show small changes in sleep duration over the last decades. Our aim was to analyze long-term patterns in self-reported sleep duration in a population-based cohort. Methods Members of the Older Finnish Twin Cohort have responded to questionnaires in 1975 (N = 30,915 individuals, response rate 89%, mean age 36 years), 1981 (24,535, 84%, 41 years), 1990 (12,450, 77%, 44 years), and 2011 (8334, 72%, 60 years). Weibull regression models were used to model the effects of follow-up time and age simultaneously. Results Sleep duration has decreased in all adult age groups and in both genders. The mean duration was in men 7.57 h in 1975 and 7.39 in 2011, and in women 7.69 and 7.37, respectively. The decrease was about 0.5 min in men and 0.9 in women per year of follow-up. In the age-group 18–34 years, mean sleep length was 7.69 h in 1975 and 7.53 in 1990. Among 35–54-year-old it was 7.57 h in 1975 and 7.34 in 2011, and in the age group of 55+ year olds 7.52 and 7.38, correspondingly. The change was largest in middle-aged group: about 23 min or about 0.6 min per year of follow-up. Conclusions There has been a slight decrease in mean sleep duration during the 36-year follow-up. Although the sleep duration was longer in 1970s and 1980s, the probable main cause for the change in this study population is the effect of aging.

Background: Sleep deprivation is often claimed to be increasingly common, but most studies show small changes in sleep duration over the last decades. Our aim was to analyze long-term patterns in self-reported sleep durationin a population-based cohort.Methods: Members ofthe Older Finnish Twin Cohort have responded to questionnaires in 1975 (N = 30,915 individuals,response rate 89%, mean age 36 years), 1981 (24,506, 84%, 41 years), 1990 (12,502,77%, 44 years), and 2011 (8510, 72%, 60 years).Weibull regression models were used to model the effects of follow-up time and age simultaneously.Results: Sleep duration has decreased in all adult age groups and in both genders.The mean duration was in men 7.57 hours in 1975 and 7.39 in 2011, and in women 7.69 and 7.37, respectively. The decrease was about 0.5minutes in men and 0.9in women per year of follow-up. In the age-group 18-34 years, mean sleep length was 7.69 hours in 1975 and 7.53 in 1990. Among 35-54-year-old it was 7.57 hours in 1975 and 7.34 in 2011, and in the age group of 55+ year olds7.52 and 7.38, correspondingly. The change was largest in middle-aged group: about 23 minutes or about 0.6 minutes per year of follow-up.Conclusions: There has been a slight decrease in mean sleep duration during the 36-year follow-up.Although the sleep duration was longer in 1970s and 1980s, the probablemain cause for the change in this study populationis the effect of aging.