Diagnosing acute nonspecific low back pain: Time to lower the red flags?

Abstract

Episodes of acute low back pain are a universal human experience (1). Usually, this is a benign, selflimiting disorder that does not require professional advice or specific treatment (2). Once someone with acute low back pain presents for care, a plethora of management guidelines are available to treating clinicians. These guidelines typically recommend that serious disorders (cauda equina syndrome, fracture, infection, inflammatory disorders, malignancy) should be excluded, using a number of "red flag" questions, before making a diagnosis of nonspecific low back pain (3). In contrast to the high-quality data available for at least some treatments of nonspecific low back pain, systematic reviews of the use of red flag questions to identify malignancy and fractures show that the strength of the evidence underpinning these screening questions is weak (4,5). Furthermore, few of the data that are available were collected in a primary care setting, where most consultations for back pain take place.In this issue of Arthritis & Rheumatism, Henscke and colleagues report on the performance of commonly recommended red flags in a prospective study of 1,172 consecutive patients presenting to a primary care setting because of acute low back pain (duration of Ͼ24 hours but Ͻ6 weeks) (6). After careful followup over 1 year, a serious cause for back pain was identified in only 11 patients (0.9%; 95% confidence interval [95% CI] 0.5-1.7%). The incidence of spinal fractures (8 [0.7%] of 1,172 patients [95% CI 0.4-1.3%]) and malignancy (none of 1,172 patients [95% CI 0-0.3%]) was much lower than the commonly quoted values for osteoporotic fractures and malignancy (ϳ4% and ϳ0.7%, respectively) (7).An important strength of this study is that data were collected from members of different health professions who provide first-contact care for acute back pain in a primary care setting. This approach also results in an important weakness of the study: only first presentations for a new episode of low back pain were considered. Serious disorders causing low back pain are likely to be more common in some other patient groups. Persons in such groups include those presenting for a second, third, or subsequent primary care consultation because of pain that is not resolving, those presenting to an emergency room, and those who had been referred for specialist care. Thus, even though the incidence of serious disease is very low at the time of first consultations for new episodes of acute low back pain, clinicians do need to keep their diagnosis of nonspecific low back pain under review during the subacute and early chronic phases of low back pain (8). Indeed, these serious disorders can develop in patients with established disabling chronic low back pain and thus cannot be disregarded regardless of how long the patient has been experiencing low back pain. With this extremely low incidence of serious disease identified following a first consultation for a new episode of acute low back pain, the large number of patients with 1 or more red flag sy...

Red flags presented in current low back pain guidelines: a review

“…Given that the risk of serious disease for patients who present to primary care with low back pain is already low (e.g., infection \0.1 %, cancer about 0.7 %), red flags are of limited use when ruling out pathology. This is in contrast to other diagnostic models such as the Ottawa ankle rule where a negative test result may decrease the probability of ankle fracture from about 15 % to less than 2 % [46][47][48]. Therefore, diagnostic models that demonstrate an increased ability to detect serious disease should be explored.…”

The Recent Trend in Diagnosis and Treatment of Chronic Low Back Pain

“…Clinical guidelines have been criticized. One study points that diagnostic procedures recommended in guidelines are not proved effective 21) . There is a study showing that red flags identifying serious conditions are not effective except for in the case of vertebral fracture [22][23][24] .…”

Red Flags: To Screen or Not to Screen?

“…The findings by Henschke et al 17 prompted Underwood 28 to write in the editorial of that same issue of the journal Arthritis and Rheumatism that "Too great a focus on addressing red flag questions may distract the clinician from delivering key information to the patient: reassurance as to the benign nature of the disorder for the vast majority of patients and the benefits of avoiding bed rest and maintaining normal activity, including work." He goes on to write that "The indiscriminate use of red flag symptoms as a trigger to order further investigations will lead to unnecessary investigations that are themselves harmful, through a combination of overmedicalizing a benign usually self-limiting disorder, the harmful effects of radiation from obtaining unnecessary radiographs and computed tomography scans, and the consequences of these investigations themselves producing false-positive results."…”

“…He goes on to write that "The indiscriminate use of red flag symptoms as a trigger to order further investigations will lead to unnecessary investigations that are themselves harmful, through a combination of overmedicalizing a benign usually self-limiting disorder, the harmful effects of radiation from obtaining unnecessary radiographs and computed tomography scans, and the consequences of these investigations themselves producing false-positive results." Underwood 28 recommends that rather than recording an exhaustive list of red flags, clinicians should consider a small number of disorders in which early diagnosis and treatment might make a big difference (ie, cauda equina syndrome, major intra-abdominal pathology, focal infections, and fractures), and use time as a diagnostic tool for the remainder. If, in the clinician's judgment, based upon skills and experience, the patient may have one of these serious conditions, appropriate investigation and treatment are indicated.…”

“…back pain, the large number of patients with at least 1 red flag symptom (80%) is of considerable concern. As noted by Underwood, 28 if nearly everyone with acute low back pain has a red flag, then the presence of a red flag will not help the clinician in deciding whether any further investigation or treatment is needed. We already are in the midst of a crisis when it comes to managing low back pain.…”