Validity and completeness of rheumatoid arthritis diagnoses in the nationwide DANBIO clinical register and the Danish National Patient Registry.

OBJECTIVES: In Denmark, patients with rheumatoid arthritis (RA) are registered in the nationwide clinical DANBIO quality register and the Danish National Patient Registry (DNPR). The aim was to study the validity of the RA diagnosis and to estimate the completeness of relevant RA cases in each registry. STUDY DESIGN AND SETTING: Patients registered for the first time in 2011 with a diagnosis of RA were identified in DANBIO and DNPR in January 2013. For DNPR, filters were applied to reduce false-positive cases. The diagnosis was verified by a review of patient records. We calculated the positive predictive values (PPVs) of the RA diagnosis registrations in DANBIO and DNPR, and estimated the registry completeness of relevant RA cases for both DANBIO and DNPR. Updated data from 2011 to 2015 from DANBIO were retrieved to identify patients with delayed registration, and the registry completeness and PPV was recalculated. RESULTS: We identified 1,678 unique patients in DANBIO or in DNPR. The PPV (2013 dataset) was 92% in DANBIO and 79% in DNPR. PPV for DANBIO on the 2015 update was 96%. The registry completeness of relevant RA cases was 43% in DANBIO, increasing to 91% in the 2015 update and 90% in DNPR. CONCLUSION: DANBIO held a high proportion of true RA cases (96%) and was found to be superior to the DNPR (79%) with regard to the validity of the diagnosis. Both registries were estimated to have a high completeness of RA cases treated in hospital care (~90%).

Establishment of age- and sex-adjusted reference data for hand bone mass and investigation of hand bone loss in patients with rheumatoid arthritis treated in clinical practice: an observational study from the DANBIO registry and the Copenhagen Osteoarthritis Study.

BACKGROUND: Rheumatoid arthritis is characterised by progressive joint destruction and loss of periarticular bone mass. Hand bone loss (HBL) has therefore been proposed as an outcome measure for treatment efficacy. A definition of increased HBL adjusted for age- and sex-related bone loss is lacking. In this study, we aimed to: 1) establish reference values for normal hand bone mass (bone mineral density measured by digital x-ray radiogrammetry (DXR-BMD)); and 2) examine whether HBL is normalised in rheumatoid arthritis patients during treatment with tumour necrosis factor alpha inhibitors (TNFI). METHODS: DXR-BMD was measured from hand x-rays in a reference cohort (1485 men/2541 women) without arthritis randomly selected from an urban Danish population. Sex- and age-related HBL/year was estimated. DXR-BMD was measured in rheumatoid arthritis patients (n = 350: at start of TNFI, and ~2 years after TNFI start), of which 135 patients had three x-rays (~2 years prior to TNFI, at start of TNFI, and ~2 years after TNFI start). Individual HBL/year prior to and during TNFI was calculated and compared to reference values. RESULTS: Estimated HBL/year varied strongly with age and sex. Compared to the reference values, 75 % of 135 patients had increased HBL prior to TNFI treatment and 59 % had increased HBL during TNFI treatment (p = 0.17, Chi-squared). In 38 % (38/101) of patients with increased HBL, HBL was normalised during TNFI treatment, whereas 47 % (16/34) of patients with normal HBL prior to TNFI had increased HBL during TNFI treatment. In the 350 patients, increased HBL during TNFI was associated with time-averaged 28-joint disease activity score (odds ratio 1.69 (95 % Confidence Interval 1.34-2.15)/unit increase, p < 0.001), and patients in time-averaged remission had lower HBL than patients without remission (0.0032 vs. 0.0058 g/cm(2)/year; p < 0.001, Mann-Whitney). CONCLUSIONS: We established age- and sex-specific reference values for DXR-BMD in a large cohort without arthritis. HBL was increased in the majority of rheumatoid arthritis patients initiating TNFI in clinical practice, and only normalised in a minority during TNFI.

Do rheumatoid arthritis patients in clinical practice benefit from switching from infliximab to a second tumor necrosis factor alpha inhibitor?

OBJECTIVE: To investigate the efficacy of switching to a second biological drug in rheumatoid arthritis (RA) patients. METHODS: Since 2000, Danish RA patients (n = 1021) receiving biological therapy have been registered in the nationwide DANBIO database. The first and second treatment series of patients, who switched therapy before 2005 (n = 235), were analysed for their reasons for switching, Disease Activity Score 28 (DAS28), DAS28 improvement, European League against Rheumatology (EULAR) response and drug survival. Most patients switched from infliximab to etanercept or adalimumab. RESULTS: Median survivals for switchers' first/second treatment were 37/92 weeks (all patients' first treatment 119 weeks). Reasons for switching were lack of efficacy (LOE; 109 patients), adverse events (AE; 72), other reasons (54). If patients experienced AE to the first drug, 15% had AE to the second. Median DAS28 improvements in first/second treatment at 3 months were: LOE switchers 1.1/1.6; AE switchers 1.5/0.8. In LOE switchers, a good/moderate EULAR response was more prevalent during the second treatment course than during the first (63% versus 54%, p = 0.02). AE switchers achieved similar EULAR responses to both treatments (59% versus 50%, p = 0.38). CONCLUSION: LOE switchers had a better clinical response to the second treatment. AE switchers responded equally well to both treatments, with a low risk of discontinuing the second drug as a result of AE. Drug survival of the switchers' second biological therapy was higher than of the first, but lower than that of non-switchers. No difference between various sequences of drugs were found. Danish post-marketing data thus support that RA patients may benefit from switching biological therapy.