By Lynn Soban, PhD, MPH, RN
Peripheral Arterial Disease (PAD) affects more than 200 million adults around the world. If identified early, PAD is highly treatable and may prevent patients from suffering major adverce cardiac events (MACE) and major adverse limb events (MALE).
The most important criterion for definition of PAD is an ankle-brachial index (ABI) below 0.90. In practice, ABI measurements are rarely performed, unless claudication symptoms (a common symptom of PAD) have been mentioned by the patient. The use of screening questionnaires enables the identification of some symptomatic patients, but these are time consuming and not established in routine primary care practice. As a result, PAD remains an underdiagnosed silent killer.
The absence of simple and fast screening strategies to identify PAD contributes to the ongoing underdiagnosis.
A recent study published in PLoS One by the German Epidemiological Consortium of Peripheral Arterial Disease examined whether asking a single question about claudication might be more effective than use of multi-item questionnaires. The question is this: “Do you get a pain in either leg on walking?”
Using data from 7 population-based cohorts, the team used a random effects meta-analysis to examine the pooled results of data from 27,945 individuals (14,052 women, age range 20–84 years). Participants were included if they had valid data on claudication, ABI, and covariates.
- One question about claudication can identify individuals with a high likelihood of low ABI.
- The sensitivity of the single-item questionnaire was 23.6% compared to 11.8% and 9.8% for the 5- and 6-item questionnaires respectively.
- The specificity of the single-item questionnaire is slightly lower, 93.3%, than those of the longer questionnaires, 98.6% and 99.1% respectively.
- The sensitivity of the single-item questionnaire increases as age increases
o Sensitivity among adults 55–65 years old = 28.5% [22.5, 35.1]
o Sensitivity among adults > 65–74 years old = 32.6% [27.3; 38.2]
The authors recommend using this single, simple question as a first screening step in all patients who are at least 40 years old, as PAD prevalence already reaches 5% at this age in both women and men in high-income countries. If individuals answer “yes,” the next step should be an ABI measurement.
While a primary ABI screening in this group of patients would be preferable, it is currently not feasible due to reimbursement issues.
The authors conclude, “…if we manage to motivate general physicians to ask their patients one question about claudication and thereby identify 20–30% of patients with mild PAD, this will be a huge step forward in comparison to the present situation, in which the percentage of patients with mild PAD recognized in general practices is close to zero.”
One question asking about pain in the leg(s) during normal walking could easily be integrated in the ascertainment of a routine medical history.
PAD awareness would be significantly improved if many patients could be identified by a single question of a general practitioner.
Adapted from: Kieback AG, Espinola-Klein C, Lamina C, et. al. One simple claudication question as first step in Peripheral Arterial Disease (PAD) Screening: A meta-analysis of the association with reduced Ankle-Brachial Index (ABI) in 27,945 subjects. PLoS ONE. 2019;14(11): e00224698.