Psoriatic arthritis, axial spondyloarthritis and rheumatoid arthritis in Norway: nationwide prevalence and use of biologic agents.

OBJECTIVE: To estimate the prevalence of psoriatic arthritis (PsA), axial spondyloarthritis (axSpA) and rheumatoid arthritis (RA) and the use of biologic agents in these diseases in Norway. METHODS: From the Norwegian Patient Registry (NPR), we identified as PsA, axSpA and RA patients ≥18 years those with ≥2 recorded episodes with diagnostic coding for index disease (L40.5, M07.0-M07.3 for PsA; M45, M46.0, M46.1, M46.8 and M46.9 for axSpA; M05-M06 for RA). We calculated the point prevalence of PsA, axSpA and RA as per the 1st of January 2017 in the Norwegian adult population (age ≥18). Dispensed disease-modifying antirheumatic drug (DMARD) prescriptions were obtained from the Norwegian Prescription Database and biologic DMARDs given in hospitals from the NPR. RESULTS: The point prevalence of PsA, axSpA, RA, and any of these diseases in total was 0.46%, 0.41%, 0.78%, and 1.56%, respectively. Among women, the prevalence of PsA, axSpA, and RA was 0.50%, 0.37%, and 1.10%, and among men 0.43%, 0.45%, and 0.46%, respectively. In 2017, 27.3% of RA patients, 25.7% of PsA patients and 35.1% of axSpA patients used biologic DMARDs. Treatment with biologics was more frequent in younger age groups in all three diseases, and became more infrequent especially after age ≥55 years. CONCLUSION: In Norway, the combined prevalence of PsA, axSpA, and RA was over 1.5%. Reflecting the good overall access to highly effective but costly biologic treatments, more than a fourth of these patients used biologic agents, which corresponds to over 0.4% of Norwegian adult population.

Cluster analysis identifies unmet healthcare needs among patients with rheumatoid arthritis.

OBJECTIVE: To identify the patterns of healthcare resource utilization and unmet needs of persistent disease activity, pain, and physical disability in rheumatoid arthritis (RA) by cluster analysis. METHOD: Patients attending the Jyväskylä Central Hospital rheumatology unit, Finland, were, from 2007, prospectively enrolled in a clinical database. We identified all RA patients in 2010-2014 and combined their individual-level data with well-recorded administrative data on all public healthcare contacts in fiscal year 2014. We ran agglomerative hierarchical clustering (Ward's method), with 28-joint Disease Activity Score with three variables, Health Assessment Questionnaire index, pain (visual analogue scale 0-100), and total annual health service-related direct costs (€) as clustering variables. RESULTS: Complete-case analysis of 939 patients derived four clusters. Cluster C1 (remission and low costs, 550 patients) comprised relatively young patients with low costs, low disease activity, and minimal disability. C2 (chronic pain, disability, and fatigue, 269 patients) included those with the highest pain and fatigue levels, and disability was fairly common. C3 (inflammation, 97 patients) had rather high mean costs and the highest average disease activity, but lower average levels of pain and less disability than C2, highlighting the impact of effective treatment. C4 (comorbidities and high costs, 23 patients) was characterized by exceptionally high costs incurred by comorbidities. CONCLUSIONS: The majority of RA patients had favourable outcomes and low costs. However, a large group of patients was distinguished by chronic pain, disability, and fatigue not unambiguously linked to disease activity. The highest healthcare costs were linked to high disease activity or comorbidities.

Patients with rheumatic diseases share similar patterns of healthcare resource utilization.

Objectives: Healthcare service needs have changed with the use of effective treatment strategies. Using data from the modern era, we aimed to explore and compare health service-related direct costs in juvenile idiopathic arthritis (JIA), psoriatic arthritis (PsA), rheumatoid arthritis (RA), and axial spondyloarthritis (AxSpA). Methods: We linked a longitudinal, population-based clinical data set from Finland's largest non-university hospital's rheumatology clinic with an administrative database on health service-related direct costs in 2014. We compared all-cause costs and costs of comorbidities between adult patients with JIA, PsA, RA, and AxSpA (including ankylosing spondylitis). We also characterized patients with high healthcare resource utilization. Results: Cost distributions were similar between rheumatic diseases (p = 0.88). In adulthood, patients with JIA displayed a similar economic burden to much older patients with other inflammatory rheumatic diseases. A minority were high utilizers: among 119 patients with JIA, 15% utilized as much as the remaining 85%. For PsA (213 patients), RA (1086), and AxSpA (277), the high-utilization proportion was 10%. Both low and high utilizers showed rather low disease activity, but in high utilizers, the patient-reported outcomes were slightly worse, with the most distinct differences in pain levels. Of health service-related direct costs, index rheumatic diseases comprised only one-third (43.6% in JIA) and the majority were comorbidity costs. Conclusions: Patients with JIA, PsA, RA, and AxSpA share similar patterns of healthcare resource utilization, with substantial comorbidity costs and a minority being high utilizers. Innovations in meeting these patients' needs are warranted.

Healthcare costs and outcomes in adult patients with juvenile idiopathic arthritis: a population-based study.

OBJECTIVES: Evidence of the economic burden and long-term outcomes of juvenile idiopathic arthritis (JIA) remains scarce. Our aim was to explore healthcare costs and long-term outcomes in adult patients with JIA. METHOD: We identified all adult patients (≥ 18 years) with JIA who visited Jyväskylä Central Hospital rheumatology unit between May 2007 and March 2016. We considered individual medians of time-dependent clinical variables. These data were linked to administrative data from the area from the fiscal year 2014, which include information on all public healthcare contacts. Healthcare utilization is presented as direct costs in euros (EUR). Factors affecting direct costs were assessed with a generalized linear model. RESULTS: In 218 patients, median 28-joint Disease Activity Score with three variables (DAS28-3) was < 2.6 in 88.6% in those aged < 30 and in 72.9% in those aged ≥ 30 years, and median Health Assessment Questionnaire (HAQ) score was < 0.5 in 85.7% and 45.4%, respectively. In the utilization data (four municipalities, 137 patients), the total annual health services-related direct costs were 432 257 EUR (mean = 3155 EUR/patient/year). Thirty-six patients (26.3%) used biological disease-modifying anti-rheumatic drugs (bDMARDs) in 2014 for a total of 355 months, and the annual cost of bDMARDs was estimated at 355 000 EUR. Those with active disease had mean costs 2.4-fold higher than those with low or no disease activity. A one-point increase in median raw HAQ incurred an average 228 EUR increase in annual costs (p = 0.03). CONCLUSION: Most adult patients with JIA seem to manage well with their arthritis, bearing in mind that there still is room for improvement in long-term outcomes.

HYDRA: a knowledge acquisition tool for expert systems that critique medical workup.

HYDRA is a computer-based knowledge acquisition tool under development to assist in the creation of expert systems which critique medical workup. To use HYDRA, a domain expert first outlines the recommended approaches to the workup of a chosen medical problem, using the Augmented Transition Network formalism. From this model, HYDRA produces a list of the various conditions for which critiquing comments may be required to react to all possible approaches that might be proposed by the user of the critiquing system. Domain-specific constraints can be used to restrict the number of conditions suggested. In this way, HYDRA assists the domain expert by providing a model for structuring the problem, and by breaking down the domain expert's work into a set of small, easily understood tasks.

Knowledge acquisition and verification tools for medical expert systems.

Expert systems require large amounts of domain knowledge for non-trivial problem solving. Experience in developing such systems has shown that the processes of acquiring domain knowledge (knowledge acquisition) and of determining whether the knowledge is consistent, complete, and correct (knowledge verification) are major problems. This paper discusses various tools developed to assist in these two processes. These tools bring additional knowledge to bear, or provide better interfaces between a knowledge engineer and the expert system's knowledge.

Spread of epileptic seizure activity in humans.

A computer-augmented approach to ictal EEG analysis has been developed. A method for determining both the predictability of one signal from another and the time delay between those two signals--the average amount of mutual information (AAMI) method--has been applied to representative seizures of two patients with focal-onset seizures and one patient with generalized seizures. High AAMI values characterized the EEG derived from the sites of the epileptic foci. AAMI values were high in all sampled brain areas in the patient with generalized seizures. Time delays were not consistent in any subject. The results indicate that the AAMI technique can differentiate focal from generalized seizures and identify the site of seizure onset.

Propagation of seizure activity in kindled dogs.

The problem of determining the location of epileptogenic foci has been studied by means of a new analysis technique, the AAMI method. This AAMI method is a generalization of the more conventional cross-correlation technique, and can be used for the determination of relationships and of time delays between simultaneously recorded EEG signals during an epileptic paroxysm. Unlike the cross-correlation function, the AAMI method is not restricted to the study of linear propagation channels. The spread of seizure activity in several seizures of 3 dogs, made epileptic by the kindling process, has been analyzed, using depth recording. The focus was located in the prepyriform cortex (PPC). The spread of activity from there to the amygdala was observed. It was found that seizures can be divided into 3 phases. In the first phase (lasting up to 5 sec after the kindling stimulus) no relationship between PPC and amygdala was found. In the second phase (5-13 sec) a strong relationship between these areas was found, with consistent delay times which decreased during this interval from 19.1 to 23.6 msec at the beginning to 11.3 to 16.0 msec at the end of the interval. In the third phase of the seizures (after about 13 sec post kindling) activity in the reported areas was found to be independent again. A possible neurophysiological interpretation of these findings is given.