How well do radiographic, clinical and self-reported diagnoses of knee osteoarthritis agree? Findings from the Hertfordshire cohort study

Abstract

ObjectiveEpidemiological studies of knee osteoarthritis (OA) have often used a radiographic definition. However, the clinical syndrome of OA is influenced by a broad range of factors in addition to the structural changes required for radiographic OA. Hence more recently several studies have adopted a clinical or self-reported approach to OA diagnosis rather than a radiographic approach. The aim of this study was to investigate agreement between radiographic OA and the clinical and self-reported diagnoses of OA.DesignData were available for 199 men and 196 women in the Hertfordshire Cohort Study (HCS), UK. Participants completed a questionnaire detailing self-reported OA. Clinical OA was defined based on American College of Rheumatology (ACR) criteria. Knee radiographs were taken and graded for overall Kellgren and Lawrence (K&L) score.ResultsThe mean (standard deviation (SD)) age of study participants was 75.2 (2.6) years and almost identical proportions of men and women. The prevalence of knee OA differed depending on the method employed for diagnosis; 21% of the study participants self-reported knee OA, 18% of the participants had clinical knee OA and 42% of the participants had radiographic OA. Of those 72 study participants with a self-reported diagnosis of knee OA 52 (72%) had a radiographic diagnosis of knee OA, while 66% (39 out of 59) of study participants with clinical knee OA had a diagnosis of radiographic knee OA. However 58% of those participants diagnosed with radiographic OA did not have either self-reported knee OA or a diagnosis of clinical OA. Therefore in comparison with the radiographic definition of OA, both the clinical and self-report definitions had high specificity (91.5% & 91.5% respectively) and low sensitivity (24.5% and 32.7% respectively).ConclusionThere is modest agreement between the radiographic, clinical and self-report methods of diagnosis of knee OA.

A diagnosis of knee osteoarthritis does not predict physical activity 2 years later in older adults: findings from the Hertfordshire Cohort Study

“…This study proved the methodology is acceptable to older adults who were able to wear an accelerometer for the required period of time and observed no significant relationships between any structural or symptomatic assessment of knee OA and subsequent PA after adjustment for confounders. Radiographic knee OA was more common than self-report or clinical knee OA which is consistent with previous studies [15,16].…”

Physical Activity Patterns Among Older Adults With and Without Knee Osteoarthritis in Six European Countries

“…However, to account for differences in radiographic and clinical OA, a subsample of the EPOSA cohort, who originally participated in the Hertfordshire Cohort Study, was closely investigated (48). The clinical definition was considered as correctly defining participants without OA (specificity of 91.5%).…”

The causal role of smoking on the risk of hip or knee replacement due to primary osteoarthritis: a Mendelian randomisation analysis of the HUNT study

“…Therefore, we acknowledge that the inverse association between smoking and TJR may both include a protective effect of smoking on OA as well as a reduced probability of TJR among smokers with OA. However, consensus on the diagnosis OA is lacking and only modest agreement has been reported between radiographic, clinical and self-reported methods of diagnosing hip and knee OA 37,38 . Despite the potential limitation of using TJR as outcome, it does have the advantage of being an unambiguous indicator of the disease burden of OA 37 .…”