Monitoring the incidence and management of inflammatory arthritis in England

Autoimmune inflammatory arthritis (IA) encompasses an overlapping group of conditions that includes rheumatoid arthritis (RA), psoriatic arthritis (PsA), axial spondyloarthritis (axSpA), and undifferentiated IA. Early diagnosis of IA and prompt treatment with disease-modifying anti-rheumatic drugs (DMARDs; e.g. methotrexate) improves outcomes for patients and increases the likelihood of remission.

In England and Wales, the quality of care for people with IA is benchmarked in the National Early Inflammatory Arthritis Audit (NEIAA). Metrics benchmarked include the time from primary care referral to initial rheumatology assessment, and the time to initiation of a DMARD. However, during the COVID-19 pandemic, mandatory data collection in NEIAA was paused, thereby preventing comparisons of care.

The aim of this report is to use the OpenSAFELY platform to replicate key metrics from NEIAA, and assess the impact of COVID-19 on care for people with new diagnoses of IA in England. The results shown below are from a study population consisting of all patients aged 18 years or above who are registered with a general practice in England that uses TPP health software.

Incidence of inflammatory arthritis diagnoses

This graph shows the monthly incidence of new IA diagnoses in England, corresponding to the appearance of new IA diagnosis codes (RA, PsA, axSpA, undifferentiated IA) in patients' primary care records. The denominator for calculating diagnostic incidence was all adults registered with a TPP general practice as of 1 April 2019 (17.7 million). The vertical hashed line in the graph corresponds to the start of the first COVID-19 lockdown in England (March 2020).

Stata Graph - incidence_twoway 0 0.1 0.2 0.3 0.4 0.5 0.6 Monthly incidence of IA diagnoses per 10,000 population Apr 2019 Oct 2019 Apr 2020 Oct 2020 Apr 2021 Oct 2021 Apr 2022 Oct 2022 Date of diagnosis Total EIA diagnoses RA PsA AxSpA Undifferentiated IA

The table below summarises the number of new IA diagnoses and corresponding diagnostic incidence (per 10,000 adult population), by year of diagnosis.

All IA diagnoses Rheumatoid arthritis Psoriatic arthritis Axial spondyloarthritis Undifferentiated IA
Count Incidence Count Incidence Count Incidence Count Incidence Count Incidence
April 2019/20 11440 6.47 6960 3.94 2665 1.51 1265 0.72 550 0.31
April 2020/21 9150 5.17 5630 3.18 1945 1.10 1135 0.64 440 0.25
April 2021/22 11045 6.25 6655 3.76 2315 1.31 1620 0.92 455 0.26

Time to initial rheumatology assessment

The table below summarises the median time, in days, from primary care referral to first assessment by a rheumatology specialist for people with new IA diagnoses, separated by date of diagnosis and by disease subtype.

Data are shown for all patients with new IA diagnoses who had their first rheumatology outpatient appointment captured and who had a minimum of 6 months of available follow-up (from 1 April 2019 to 31 March 2022). Rheumatology outpatient clinics were defined by the presence of a '410' treatment function code. A proxy of primary care referral date was used, defined as the last primary care appointment before the first rheumatology appointment.

Median time to rheumatology assessment (days)
Overall Apr 2019-Jun 2019 Jul 2019-Sep 2019 Oct 2019-Dec 2019 Jan 2020-Mar 2020 Apr 2020-Jun 2020 Jul 2020-Sep 2020 Oct 2020-Dec 2020 Jan 2021-Mar 2021 Apr 2021-Jun 2021 Jul 2021-Sep 2021 Oct 2021-Dec 2021 Jan 2022-Mar 2022
All IA diagnoses 19 22 21 19 20 18 18 17 16 17 21 19 20
Rheumatoid arthritis 17 20 19 16 18 15 16 15 14 15 19 16 18
Psoriatic arthritis 22 26 28 23 26 23 21 21 20 21 27 21 22
Axial spondyloarthritis 27 26 34 27 23 34 27 21 25 27 28 33 28
Undifferentiated IA 18 26 20 16 21 22 15 15 20 15 19 14 21

The graph below shows the proportion of patients who received their first rheumatology assessment within 3 weeks of primary care referral. The 3-week target is recommended in national guidelines (NICE). Trends during each full-year period from April are shown.

Stata Graph - Graph 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Mean proportion assessed within 3 weeks of referral Apr 2019 Oct 2019 Apr 2020 Oct 2020 Apr 2021 Oct 2021 Apr 2022 Date of first rheumatology appointment

Summarised below is the regional variation in rheumatology assessment times for new IA patients. Results are compared by time period: Year 1 (1 April 2019 to 31 March 2020); Year 2 (1 April 2020 to 31 March 2021); and Year 3 (1 April 2021 to 31 March 2022).

Stata Graph - regional_qs2_bar_GP 0 0.2 0.4 0.6 0.8 1.0 Proportion of patients Yorkshire/Humber West Midlands South West South East North West North East London East Midlands East National Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Time from referral to rheumatology assessment Within 3 weeks Within 6 weeks More than 6 weeks

Time to prescription of a DMARD in primary care

The graph below shows the proportion of patients who were prescribed conventional synthetic DMARDs (csDMARDs: methotrexate, leflunomide, sulfasalazine or hydroxychloroquine) in primary care within 6 months of their first rheumatology appointment. Trends during each full-year period from April are shown. Decreases were observed in March 2020 and April 2020, corresponding to the start of the first COVID-19 lockdown in England.

Data are shown for all patients with new diagnoses of RA, PsA or undifferentiated IA who had their first rheumatology appointment captured and a minimum of 6 months of available follow-up (from 1 April 2019 to 31 March 2022). Data for patients with axSpA are not included, due to small numbers of these patients receiving csDMARDs. Only primary care-issued prescriptions for DMARDs are captured, representing shared-care prescribing between primary care and secondary care clinicians; secondary care-issued prescriptions are not currently captured.

Stata Graph - Graph 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Mean proportion prescribed csDMARD in primary care within 6 months Apr 2019 Oct 2019 Apr 2020 Oct 2020 Apr 2021 Oct 2021 Apr 2022 Date of first rheumatology appointment

Summarised below is the regional variation in time to first csDMARD prescription in primary care. Results are compared by time period: Year 1 (1 April 2019 to 31 March 2020); Year 2 (1 April 2020 to 31 March 2021); and Year 3 (1 April 2021 to 31 March 2022).

Stata Graph - regional_csdmard_bar 0 0.2 0.4 0.6 0.8 1.0 Proportion of patients Yorkshire/Humber West Midlands South West South East North West North East London East Midlands East National Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Year 3 Year 2 Year 1 Time to first csDMARD in primary care Within 3 months Within 6 months None within 6 months

Choice of first DMARD

The table below shows the choice of first DMARD medication, separated by year, for IA patients who were prescribed at least one csDMARD in primary care within 6 months of diagnosis.

Data are shown for patients with new diagnoses of RA, PsA or undifferentiated IA who had their first rheumatology appointment captured and a minimum of 6 months of available follow-up (from 1 April 2019 to 31 March 2022). Data for patients with axSpA are not included, due to small numbers of these patients receiving csDMARDs. Similarly, prescriptions for leflunomide are not shown, as these represent <2% of DMARD prescriptions. Only primary care-issued prescriptions for DMARDs are captured, representing shared-care prescribing between primary and secondary care clinicians; secondary care-issued prescriptions are not currently captured.

First csDMARD prescribed in primary care (%)
Overall Apr 2019-Jun 2019 Jul 2019-Sep 2019 Oct 2019-Dec 2019 Jan 2020-Mar 2020 Apr 2020-Jun 2020 Jul 2020-Sep 2020 Oct 2020-Dec 2020 Jan 2021-Mar 2021 Apr 2021-Jun 2021 Jul 2021-Sep 2021 Oct 2021-Dec 2021 Jan 2022-Mar 2022
Methotrexate 62.3 66.3 67.0 66.8 60.5 43.5 57.6 61.2 60.9 62.7 63.6 63.0 66.4
Sulfasalazine 15.4 12.6 12.4 12.8 15.4 25.9 21.2 15.9 16.8 14.6 13.6 15.2 13.4
Hydroxychloroquine 22.3 21.1 20.6 20.3 24.1 30.6 21.2 22.9 22.4 22.8 22.8 21.8 20.1