The National Swedish Lymphoma Register - a systematic validation of data quality.

BACKGROUND AND PURPOSE: The Swedish Lymphoma Register (SLR) was initiated in the year 2000 with the aim to monitor quality of care in diagnostics, treatment and outcome of all lymphomas diagnosed nationally among adults. Here, we present the first systematic validation of SLR records as a basis for improved register quality and patient care. PATIENTS AND METHODS: We evaluated timeliness and completeness of register records among patients diagnosed with lymphoma in the SLR (n = 16,905) compared with the National Cancer Register for the period 2013-2020. Comparability was assessed through evaluation of coding routines against national and international guidelines. Accuracy of 42 variables was evaluated through re-abstraction of data from medical records among 600 randomly selected patients diagnosed in 2016-2017 and treated across all six Swedish healthcare regions.  Results: Completeness was high, >95% per year for the period 2013-2018, and >89% for 2019-2020 compared to the National Cancer Register. One in four patients was registered within 3 months, and 89.9% within 2 years of diagnosis. Registration instructions and coding procedures followed the prespecified guidelines. Missingness was generally low (<5%), but high for occasional variables, for example, those describing maintenance and consolidative treatment. Exact agreement of categorical variables was high overall (>80% for 24/34 variables), especially for treatment-related data (>80% for 17/19 variables). INTERPRETATION: Completeness and accuracy are high in the SLR, while timeliness could be improved. Finetuning of variable registration guided by this validation can further improve reliability of register reports and advance service to lymphoma patients and health care in the future.

Increased Risk of Hip Fracture in Patients with Lymphoma, a Swedish Population Study of 37,236 Lymphoma Patients.

Increased bone loss has been noted in lymphoma patients; however, the incidence of hip fracture is not known. The aim of our study was to explore the risk for hip fracture in patients with lymphoma compared with the entire Swedish population. The risk of hip fracture was determined in a retrospective population cohort study of adult Swedish lymphoma patients (n = 37,236), diagnosed 1995-2015 and compared with the entire Swedish population during the same period. The incidence of hip fracture in lymphoma patients was higher in women than in men, increased by age, and decreased by calendar year as also demonstrated in the total population. 2.2% of the men and 4.7% of women with lymphoma sustained a hip fracture. For the total group of females, the hazard ratio (HR) was 1.19 (95% CI 1.11-1.28) and for men, the hazard ratio was 1.06 (95% CI 0.97-1.17) compared with the Swedish population. The HR for hip fracture (2016) was 2.80 (95% CI 1.20-6.53), 2.04 (95% CI 1.30-3.20), 1.56 (95% CI 1.21-2.01), 1.08 (95% CI 0.89-1.30), and 1.07 (95% CI 0.92-1.25) in females aged 40, 50, 60, 70, and 80 years, respectively. Corresponding figures for men were not significant in 2016. Unmarried men with lymphoma had a two times higher risk for hip fracture (HR 2.02 95% CI 1.63-2.50) compared with married men. Patients with lymphoma had an increased risk of hip fracture, especially younger women and unmarried men. The incidence of hip fracture is decreased by calendar year in the lymphoma patients and the entire Swedish population.