The prevalence of axial spondyloarthritis in the UK: a cross-sectional cohort study.

BACKGROUND: Accurate prevalence data are important when interpreting diagnostic tests and planning for the health needs of a population, yet no such data exist for axial spondyloarthritis (axSpA) in the UK. In this cross-sectional cohort study we aimed to estimate the prevalence of axSpA in a UK primary care population. METHODS: A validated self-completed questionnaire was used to screen primary care patients with low back pain for inflammatory back pain (IBP). Patients with a verifiable pre-existing diagnosis of axSpA were included as positive cases. All other patients meeting the Assessment of SpondyloArthritis international Society (ASAS) IBP criteria were invited to undergo further assessment including MRI scanning, allowing classification according to the European Spondyloarthropathy Study Group (ESSG) and ASAS axSpA criteria, and the modified New York (mNY) criteria for ankylosing spondylitis (AS). RESULTS: Of 978 questionnaires sent to potential participants 505 were returned (response rate 51.6 %). Six subjects had a prior diagnosis of axSpA, 4 of whom met mNY criteria. Thirty eight of 75 subjects meeting ASAS IBP criteria attended review (mean age 53.5 years, 37 % male). The number of subjects satisfying classification criteria was 23 for ESSG, 3 for ASAS (2 clinical, 1 radiological) and 1 for mNY criteria. This equates to a prevalence of 5.3 % (95 % CI 4.0, 6.8) using ESSG, 1.3 % (95 % CI 0.8, 2.3) using ASAS, 0.66 % (95 % CI 0.28, 1.3) using mNY criteria in chronic back pain patients, and 1.2 % (95 % CI 0.9, 1.4) using ESSG, 0.3 % (95 % CI 0.13, 0.48) using ASAS, 0.15 % (95 % CI 0.02, 0.27) using mNY criteria in the general adult primary care population. CONCLUSIONS: These are the first prevalence estimates for axSpA in the UK, and will be of importance in planning for the future healthcare needs of this population. TRIAL REGISTRATION: Current Controlled Trials ISRCTN76873217.

The prevalence of inflammatory back pain in a UK primary care population.

OBJECTIVE: Inflammatory back pain (IBP) is the earliest and most common symptom of axial SpA. However, there is very little information about the prevalence of IBP in the UK. In this cross-sectional cohort study we examined the prevalence of IBP in a UK primary care population using three published IBP criteria. METHODS: Potential participants aged 18-80 years were identified from the records of a large general practice in Norfolk, UK, with 17 177 patients. Read codes were used to identify those who had consulted their general practitioner on at least one occasion with back pain. A self-completed screening questionnaire was sent to a sample of 978 patients, enquiring about symptoms of IBP and extra-spinal manifestations of SpA. Questionnaire responses were used to determine whether patients met the Assessment of SpondyloArthritis international Society (ASAS), Calin and Berlin IBP criteria. RESULTS: Five hundred and five completed questionnaires were returned (response rate 51.6%). The median age of respondents was 60 years [interquartile range (IQR) 48-67] and 44.8% were male. The minimum prevalence of IBP among patients with at least one previous consultation for back pain was 7.7% (95% CI 6.2, 9.5) using the ASAS criteria, 13.5% (11.5, 15.8) using the Calin criteria and 15.4% (13.3, 17.8) using the Berlin criteria. There was no significant difference in prevalence between men and women, and between different age groups. Extrapolated to the practice population as a whole, the minimum prevalence of IBP in a UK primary care population is 1.7-3.4%. CONCLUSION: The prevalence of IBP varies significantly depending on the criteria used for classification.

A methodology for the functional comparison of coding schemes in primary care.

There has been massive investment in the development of clinical terminologies for use in electronic patient records. However, there has been little published evidence for the added value for primary care that implementation of such a terminology would offer. This paper outlines a methodology that has been used to compare two existing coding schemes (Read codes 5 byte set and Clinical Terms Version 3-CTV3) and demonstrates their relative performance using a certainty-agreement diagram. In the study described, CTV3 offers improved accuracy and consistency with improved usability. The potential advantages of the recently released terminology, SNOMED Clinical Terms, are briefly considered in this context.

Randomised crossover trial comparing the performance of Clinical Terms Version 3 and Read Codes 5 byte set coding schemes in general practice.

OBJECTIVE: To determine whether Clinical Terms Version 3 provides greater accuracy and consistency in coding electronic patient records than the Read Codes 5 byte set. DESIGN: Randomised crossover trial. Clinicians coded patient records using both schemes after being randomised in pairs to use one scheme before the other. SETTING: 10 general practices in urban, suburban, and rural environments in Norfolk. PARTICIPANTS: 10 general practitioners. SOURCE OF DATA: Concepts were collected from records of 100 patient encounters. MAIN OUTCOME MEASURES: Percentage of coded choices ranked as being exact representations of the original terms; percentage of cases where coding choice of paired general practitioners was identical; length of time taken to find a code. RESULTS: A total of 995 unique concepts were collected. Exact matches were more common with Clinical Terms (70% (95% confidence interval 67% to 73%)) than with Read Codes (50% (47% to 53%)) (P < 0.001), and this difference was significant for each of the 10 participants individually. The pooled proportion with exact and identical matches by paired participants was greater for Clinical Terms (0.58 (0.55 to 0.61)) than Read Codes (0.36 (0.33 to 0.39)) (P < 0.001). The time taken to code with Clinical Terms (30 seconds per term) was not significantly longer than that for Read Codes. CONCLUSIONS: Clinical Terms Version 3 performed significantly better than Read Codes 5 byte set in capturing the meaning of concepts. These findings suggest that improved coding accuracy in primary care electronic patient records can be achieved with the use of such a clinical terminology.

Info-tsunami: surviving the storm with data quality probes.

As a result of the rapid expansion of electronically available clinical knowledge, clinicians are faced with potential information overload (info-tsunami). The use of data quality probes (DQPs) in primary care can encourage clinicians' awareness of, and improvement in, data quality entry over time. DQPs can also highlight areas of potential error or omission as well as good practice, which can impact directly upon the quality of patient care. In this paper, five specific conditions have been subjected to the use of a series of DQPs over a five-year period in order to assess and measure the performance of different initiatives on the quality of data capture and patient care.

The Certainty-Agreement diagram: comparing the functionality of coding schemes in primary care clinical information systems.

Despite enormous investment of effort and resources there are few formal comparative evaluations between different coding schemes. We have recently described a methodology of a randomised crossover trial comparing the performance of Clinical Terms Version 3 (CTV3) and Read Codes 5 Byte set (RC5B) coding schemes in General Practice. 1 This study looked at the comparative performance of the two coding schemes by 10 general practitioners using a total of 995 concepts extracted from clinical records. This paper describes the use of the Certainty-Agreement diagram in providing a graphical representation of comparative functionality.

Data quality probes-exploiting and improving the quality of electronic patient record data and patient care.

Increasing reliance is being placed on electronic medical records to support clinical care and achieve improved quality standards. In order for clinical information systems (CIS) to deliver excellence the data within it needs to be complete, consistent and accurate. This capture of data is critical but forms only part of the procedure in delivering quality health care during the clinician-patient encounter. A number of processes are involved in this encounter, each of which has to be performed flawlessly to deliver a perfect outcome. This paper outlines a method of assessing the quality of these processes involved in healthcare provision and data quality within a CIS. It proposes the principle of Data Quality Probes (DQP) to assess the performance of the whole encounter system. The main feature of this is the generation of a query which clinical knowledge predicts should not retrieve any cases in a system performing flawlessly. Any cases retrieved (which fail the DQP) indicate an error in either data quality or clinical judgment. This approach is applied practically within the paradigm of a UK family practice testing the hypothesis that a series DQPs can provide a valuable method for monitoring both the data accuracy of a CIS and the provision of quality patient care.