Introduction

‘Non-specific’ low back pain (LBP) is the guideline-recommended label for most (90–95% [1]) LBP. The label refers to LBP of unknown or uncertain origin and represents a diagnosis of exclusion, when specific pathologies (e.g. malignancy, cauda equina syndrome) have been ruled out [2,3,4]. Nonetheless, the label receives criticism [5]. Critics of the label claim it is of limited relevance to clinical practice, unacceptable to patients, provides no structural basis for LBP, and does not guide treatment choices [6,7,8].

Clinicians often use other labels to describe, or provide a structural basis, for ‘non-specific’ LBP [9, 10]. For example, a survey study of 1,093 primary-contact clinicians found that 74% think it is possible to identify the source of non-specific LBP [8]. Proposed structural sources of non-specific LBP include the intervertebral discs, facet joints, lumbar ligaments, and lumbar muscles. Popular diagnostic labels indicating pathology or damage of these structures include ‘disc bulge’, ‘degeneration’, ‘arthritis’, and ‘lumbar sprain’ [5]. Like non-specific LBP, these labels also receive criticism for a number of reasons: (1) The clinical tests used to identify these potential structural sources of LBP (e.g. facet joint) have low validity [11]; (2) pathologies represented by these labels are common among asymptomatic individuals [12]; (3) LBP is a multifactorial subjective experience[3]—where nociception may only be one contributor—so focussing only on structure may provide an inaccurate understanding of LBP; (4) there are concerns that certain labels may legitimise unnecessary tests (e.g. diagnostic imaging) and ineffective treatments (e.g. facet joint injections and surgeries) [13]; and (5) certain labels may influence individuals’ beliefs about physical activity, work capacity and recovery.

We conducted an online randomised controlled experiment with 1447 participants which examined the effect of providing individuals with and without LBP with six different labels: disc bulge, degeneration, arthritis, lumbar sprain, non-specific low back pain, and episode of back pain [6]. We found that lumbar sprain, non-specific LBP, and episode of back pain reduced perceived need for imaging, surgery and second opinion compared to disc bulge, degeneration, and arthritis among both individuals with and without LBP. They also reduced perceived seriousness of LBP and increased recovery expectations. We found little to no differences in beliefs about physical activity and work across the six labels. Although our experiment provided evidence that the labels disc bulge, degeneration, and arthritis may medicalise LBP through encouraging imaging and surgery for non-specific LBP, there is a need to further explore what different labels mean to individuals with LBP and the public, and how a label might potentially influence their treatment preferences.

This paper reports the results of a content analysis of free-text data collected in our experiment that examined participants’ thoughts/feelings and expectations for treatment evoked by the diagnostic labels.

Methods

Study design and data source

We performed a content analysis of free-text responses collected in an online randomised experiment [6]. The trial was a six-arm, parallel group, superiority experiment with blinded participants. The experiment examined the effect of six labels (disc bulge, degeneration, arthritis, lumbar sprain, non-specific LBP, and episode of back pain) on beliefs and management preferences among individuals with and without LBP.

We chose the labels disc bulge, degeneration, and arthritis as they are commonly used terms on imaging reports, and are of questionable clinical relevance [6]. In the qualitative literature, these labels are proposed to carry negative connotations. Further, they are included in medical disease classification systems (e.g., ICD-11). We selected lumbar sprain as it is included in medical disease classification systems; it is commonly used by clinicians for LBP with no specific clear structural cause; and that patients perceive this diagnosis as an injury [6]. We selected  non-specific LBP as it is the guideline-recommended term for most LBP, but  is criticised by clinicians [6]. We selected episode of back pain to describe the symptom of LBP without attaching any structural cause [6].

The study was approved by The University of Sydney Human Research Ethics Committee (2019/539).

Recruitment and participants

Recruitment and data collection took place from 12 October 2019 to 6 December 2019. Participants were recruited through Qualtrics (www.qualtrics.com). Qualtrics uses existing, nationally representative panels of individuals who have previously agreed to participate in research [6]. Participants had to be 18 years or older, able to read and write English, and be living in Australia, Canada, or Ireland. We recruited three groups of participants across our six labels [6]:

  1. 1.

    Adults who have had LBP in the past week and have received formal treatment for low back pain at any time in their life (e.g. treatment from a doctor, physiotherapist, chiropractor, surgeon, or any other healthcare provider)

  2. 2.

    Adults who have had low back pain in the past week and have never received formal treatment for LBP

  3. 3.

    Adults who are pain-free and have never experienced an episode of low back pain (lasting for at least 24 h) in their lifetime

Participants were asked to read a scenario about experiencing LBP (Box 1) and were then randomised to one of the six labels using the web-based, randomisation allocation system provided by Qualtrics [6].

Data collection

Participants provided information on demographics, and where applicable, healthcare utilisation and low back symptoms. This included data on age, gender, education level, country of residence, employment status, anxiety and depressive symptoms, history of low back pain, history of receiving lumbar imaging (e.g. MRI) or lumbar surgery, history of sick leave due to low back pain, previous low back diagnoses received, duration of current low back pain, and current pain (measured using the 0–10 Numerical Rating Scale) and disability (measured using the Oswestry Disability Index) levels. Details of these data are reported elsewhere [6].

Participants read a vignette describing a patient with low back pain, and were then randomised to one of six labels. The labels were accompanied by a brief explanation.

  1. 1.

    Disc bulge. Discs are the soft cushions of tissue between the bones in your spine. They are shock absorbers for your spine. They are tough on the outside, and soft on the inside. A bulge is when the soft part pushes out of its normal position.

  2. 2.

    Degeneration of the spine. As you get older, joints and cartilage in your spine can break down and lose their water content. Degeneration is a kind of wear and tear of the spine.

  3. 3.

    Arthrtis of the spine. Your spine is made up of different bones, joints, and the discs in between. Discs are like the cushions of the spine. As you get older, bones, joints and discs wear out, break down and can get inflamed, which leads to pain.

  4. 4.

    Lumbar sprain. Lots of soft tissues such as muscles, ligaments and tendons support the spine. You have pulled or torn one of these soft tissues.

  5. 5.

    Non-specific low back pain. You have tension, soreness, stiffness in the back, but I'm not able to say for sure which structure in your back the pain is coming from.

  6. 6.

    An episode of low back pain.' [no description provided].

After each label in the vignette, the health professional reassures the patient that the prognosis is good and returning to activities is safe (Box 1)

In this analysis we focused on free-text responses to two questions:

  1. 1.

    When you hear the term [one of the six labels], what words or feelings does this make you think of? Please list.

  2. 2.

    What treatment (s) (if any) do you think a person with [one of the six labels] needs? Please list.

Data analysis

We performed a content analysis on the free-text responses to both questions. Uninformative responses (e.g.,“I don’t want to answer this question”) were not coded. Content analysis combines both qualitative and quantitative methods, allowing both the content and frequency of categories to be reported [14, 15]. Content analysis is an appropriate research method for examining text data [16], and has been used in a previous study to examine people's responses to different labels for rotator cuff disease [15, 17].

Themes arising from each question were developed iteratively. In a Microsoft excel spreadsheet, two authors (MOK and ZM) first read responses independently to familiarise themselves with the content, took notes and developed a coding framework. Excel files were exchanged, and codes compared for each response. Disagreements were resolved over two meetings. Coding was refined collaboratively between MOK and ZM. For example, if there were separate codes for the treatments massage and spinal manipulation, agreement was reached to code this as manual therapy. Responses could be coded to multiple themes. For example, a response stating “Pain for the rest of my life” could be coded as both pain and poor prognosis. A response stating “Fear of being in a wheelchair for life” could be coded as fear, poor prognosis, and disability.

For Question 2 on treatments, we developed both themes and sub-themes for exercise, rest and medicine using the same process. For exercise, we developed subthemes for type of exercise mentioned (e.g. yoga, strengthening exercise, walking, aquatic exercise), if exercise was expressed with caution (e.g. light or gentle exercise only), or if exercise was combined with rest. For rest, we developed a subtheme for bed rest. For medicine, we developed subthemes for types of medicines (e.g. opioids, muscle relaxants, anti-inflammatories).

Descriptive statistics (counts and percentages) were used to summarise the results of the content analysis.

Results

In our online trial, 1447 participants were randomised to one of six labels [6]. After excluding participants who did not complete a primary or secondary outcome, 1375 participants (retention rate 95%) were included in the analyses.

Baseline characteristics were similar between the six randomised groups. Participants were on average 41.7 years old and 54.4% were female. 26.1% (n = 359) of participants were pain-free and had no history of LBP; 36.9% (n = 507) had LBP and a history of care-seeking; and 37% (n = 509) had LBP and no history of care-seeking. Most participants (n = 522 [37.9%]) had LBP for greater than 12 weeks. Almost one quarter (n = 340 [24.7%]) of participants had a history of imaging for LBP. A small minority of participants had a history of surgery for LBP (n = 50 [3.6%]). Just over one quarter (n = 384 [27.9%]) of participants had previously received a diagnostic label for their LBP. See Supplementary File 2 for more information on participant characteristics.


We analysed 2546 free-text responses (1290 from Question 1 and 1256 from Question 2). We excluded 85 and 119 uninformative responses from Question 1 and Question 2, respectively.

Question 1: When you hear the term [one of the six labels], what words or feelings does this make you think of?

Ten themes emerged from the content analysis for Question 1. These were:

  • Pain— responses referring to pain, aches, soreness, spasms, tension.

  • Tissue damage—responses referring to a lumbar structure or an injury.

  • Disability—responses referring to difficulty or limitations in current or future functions (e.g. movement, physical activity, sleep, work, hobbies, or any other activities of daily living).

  • Anxiety and Fear—responses referring to anxiety, fear, worry, being scared or frightened.

  • Depression—responses referring to depression, hopelessness, guilt, sadness, crying, irritability, feeling down or low.

  • Poor prognosis—responses referring to no cure, not recovering or getting better, chronicity, permanent pain/disability.

  • Good prognosis—responses referring to getting better, easy to fix, temporary pain/disability.

  • Uncertainty—responses referring to uncertainty, confusion, or feeling unsure.

  • Aging—responses referring to getting old, being old, or the aging process.

  • Imaging/treatment—responses referring to desire to get imaging (e.g. x-ray or MRI) or any form of treatment (e.g. exercise, massage).

Pain was the most frequent theme described by participants across the different labels with the exception of degeneration (see Table 1). Poor prognostic outcomes were frequent themes for degeneration (28%), arthritis (25%) and disc bulge (24%), while participants evoked positive prognostic outcomes for the labels lumbar sprain (29%), non-specific LBP (20%) and episode of back pain (29%). Anxiety and fear were more frequently evoked among participants in the disc bulge (20%), arthritis (23%), and degeneration (25%) groups. Concerns about tissue damage were lowest for non-specific LBP and episode of back pain. Feelings of uncertainty were notably higher for non-specific LBP (41%) compared to the other five labels. Responses that reflected an aging process were highest for degeneration (23%) and arthritis (16%), but did not emerge for lumbar sprain (0%), non-specific LBP (0%) or episode of back pain (0%) (Tables 1 and 2).


Frequently reported themes identified in the coding process for each label are presented in Table 1. Counts and percentage data are colour coded in six different shades of orange from 0 to 60% to help demonstrate the different frequency of themes between the labels. Reported in Table 2 are examples of participants’ feelings for each label.

Table 1 10 themes suggested for each LBP label
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Table 2 Examples of participants’ open-ended responses across labels
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Question 2: What treatment(s) (if any) do you think a person with (one of the six labels) needs? Please list.

Twenty-eight treatment themes emerged from the content analysis for Question 2. Here we have presented the ten most frequently reported treatments across each label. These were:

  • Exercise – responses referring to exercise, stretching, strengthening (e.g. core stability exercises), walking, running, cycling, yoga, pilates, or aquatics (e.g. swimming, hydrotherapy).

  • Medicine—responses referring to medicines, pain relievers, opioids, paracetamol, ‘over-the-counter’ medication, muscle relaxants, or anti-inflammatories.

  • Rest—responses referring to rest, taking it easy, giving up or cutting down on activities.

  • No treatment/stay active—responses referring to continuing usual activities, staying active with no need for formal treatment.

  • Surgery—responses referring to any surgical procedure.

  • Physiotherapy—responses specifically referring to physiotherapy.

  • Chiropractic—responses specifically referring to chiropractic.

  • Manual therapy—responses referring to massage, spinal manipulation, or other ‘hands on’ treatment approaches.

  • Heat—responses referring to heat, hot packs, or hot baths/showers.

  • Cold—responses referring to cold, cool packs, ice or cryotherapy

  • Lifestyle changes—responses referring to lifestyle changes, getting more sleep, weight loss, dietary changes, or drinking more water.

  • Specialist opinion—responses referring to seeing a specialist (e.g. a consultant).

  • Activity modification—responses referring to doing activities in a modified manner (e.g. lifting less, bending knees while lifting).

  • Creams/gels—responses referring to self-applied rubs, lotions, gels, or creams (e.g. deep heat).

  • Education/advice—responses referring to finding out more about the complaint, or getting advice on managing it.

Exercise and medicine were the most common treatment suggestions across all labels (see Table 3). Surgery commonly emerged for disc bulge (25%), degeneration (17%) and to a lesser extent arthritis (9%) and lumbar sprain (7%). Surgery did not emerge as a treatment option for non-specific LBP and episode of back pain. Rest commonly emerged for lumbar sprain (37%), non-specific LBP (31%), episode of back pain (28%) and disc bulge (23%). Heat emerged more commonly for lumbar sprain (20%), episode of back pain (21%), and non-specific LBP (14%) compared to disc bulge (7%), degeneration (6%) and arthritis (5%). No treatment required only emerged for lumbar sprain (12%), non-specific LBP (10%), and episode of back pain (4%).

Table 3 10 most frequently reported treatments for each LBP label
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The ten most frequent treatments are presented in Table 3. Table 4 displays the other 18 treatments, that were mentioned less often (e.g. footwear, psychological treatment).

Table 4 Summary of overall treatment suggestions for all six labels
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Counts and percentage data are colour coded in five different shades of green from 0 to 50%, to help convey differences in treatment suggestions between the labels.

Although less than half of the participants suggested exercise as a viable treatment across the labels, it was the most frequently (n = 511 [41%]) suggested treatment (see Table 4). These responses reflected a sense of caution when considering exercise by either modifying its intensity or combining with sedentary behaviour. Many participants suggesting exercise, (40%; n = 203) qualified its intensity with the adverbs ‘light’, ‘mild’, ‘gentle’, ‘low-impact’, ‘caution’, or ‘slow’. For example: “rest and slow exercise”, “regular exercise with caution do not over extend”, “take it easy with light exercise”, “do little bits of exercise but don’t overdo it” and “Light to average exercise”.

Overall, a combination of ‘rest’ and ‘exercise’ was suggested by 122 (24%) participants. For example: “Exercise, rest, little things that won’t put strain on her back”, “You need to rest, do some sort of light exercise to somehow move your muscle down there.”, “Rest and slow light exercises”, “Some rest, some exercises”, “Limited stress to the area but some movement to keep it limber” and “Rest for a few days followed with gentle stretching and exercise.”

Discussion

Our analysis found that the six LBP labels evoked different expressions and treatment choices. Overall, poor prognosis emerged for disc bulge, degeneration, and arthritis, while good prognosis emerged for lumbar sprain, non-specific LBP, and episode of back pain. Thoughts of tissue damage were less common among participants in the non-specific LBP and episode of back pain groups compared to disc bulge, degeneration, arthritis, and lumbar sprain. Feelings of uncertainty and confusion frequently emerged for non-specific LBP. Surgery as a treatment option was high for disc bulge, degeneration, and arthritis compared to lumbar sprain, non-specific LBP, and episode of back pain.

Surgery was commonly mentioned by participants labelled with disc bulge, degeneration, and to a lesser extent arthritis and lumbar sprain, but not by participants labelled with non-specific LBP and episode of back pain. This broadly aligns with our quantitative results that showed participants who received a label of disc bulge, degeneration, and arthritis were more willing to undergo surgery compared to participants labelled with lumbar sprain, non-specific LBP, and episode of back pain [6]. Perceptions of good prognosis in the lumbar sprain, non-specific LBP, and episode of back pain groups, and poor prognosis in the disc bulge, arthritis, and degeneration groups also align with our trial results. Our quantitative results displayed that labels of disc bulge, degeneration and arthritis increased perceived seriousness of LBP and reduced recovery expectations compared to lumbar sprain, non-specific LBP, and episode of back pain. Overall, both analyses show that lumbar sprain, non-specific LBP, and episode of back pain should be preferred over labels of disc bulge, degeneration and arthritis for communicating with patients who have non-specific LBP. Our findings also align with other qualitative research that labels such as disc bulge and degeneration are perceived to be threatening and representative of problems that are difficult to treat [18, 19].

Exercise was the most frequently suggested treatment in our study and aligns with our quantitative data that found little to no differences in beliefs about physical activity between our six labels [6]. While preference for exercise is aligned with the evidence and indicates a positive finding, 40% attached descriptors of light, mild or gentle exercise and another 24% combined exercise with rest. The perception that exercising should be performed cautiously when a person has back pain aligns with the findings of several cross-sectional surveys of attitudes and beliefs about LBP [20,21,22]. Alternatively, expressing some caution may be a reasonable way of combining relative rest and movement before a return to full physical activity. Understanding how patients conceptualise rest and staying active, together with their broader feelings about exercise for LBP, are important concepts to explore in the consultation and can inform strategies for how we best communicate this information [23, 24].

A commonly held view among clinicians—based on limited evidence—is that patient expectations drive use of treatments discordant with recommendations in clinical guidelines such as opioids, electrotherapy, traction, and injections [25, 26]. However, very few participants in our study sample suggested these treatments for LBP. The belief that patient expectations drive poor care needs to be challenged, and attention should instead be placed on targeting known drivers of poor care (e.g. vested interests, funding arrangements) [27].

This study has many strengths. We used mixed-methods to investigate general population perceptions about LBP labels. Our online trial used best methods including randomisation, concealed allocation and a sample size calculation [6]. We included a broad demographic of people with and without a lived experience of LBP and care-seeking for the problem. There was a high response rate to the two free-text response questions. Themes were derived from the data by two researchers and independently coded.

This study also has limitations. Online recruitment may select participants who are different to patients in real-world settings. Our assessment was only at a single time point immediately after the labels were given; perceptions, both in terms of thoughts and treatment decisions, may change as patients reflect over time [6]. Participants’ ability to name treatments may have been limited by their prior experience or exposure—meaning that less well understood/known treatments (e.g. injections) may have been less likely to be mentioned. We did not stratify our results based on the patient's pain level, a characteristic that could also influence patient expectations of care. Regarding medicines, although some participants specifically mentioned opioids, many used more generic descriptors such as medicines or pain relievers only. It is not possible to know whether or not respondents had specific medicines such as opioids in mind. Other labels not investigated in this study (e.g. disc herniation) may have evoked different feelings and perceived treatment needs.

Several studies suggests that many patients expect a specific diagnosis that both explains their pain and leads to successful treatment [28,29,30]. However, our findings indicate potential harms that arise from use of structurally specific diagnoses when compared to less structural terms, such as non-specific LBP or episode of back pain. This may represent a challenge for clinicians. While fulfilling patient expectations is only inconsistently associated with successful treatment outcomes [31,32,33,34,35,36], negative reactions to messaging need to be carefully managed in clinical practice. Future research will be required to explore how clinicians can best communicate a symptom—with empathy—when no structural diagnosis can be accurately made, and how best to integrate this information into a comprehensive explanation that meets patient needs.

Future research should also explore clinician, patient and broader system (e.g. work, compensation systems, health systems) acceptability of the labels found to be associated with more positive beliefs about prognosis in this study (lumbar sprain, non-specific LBP, and episode of back pain). Among clinicians, non-specific LBP is not viewed as a legitimate diagnosis that patients will accept, and some think it may increase patients’ desire for imaging and specialist opinions [2, 12]. This means clinicians might be surprised by the results of our online trial. However, the feelings of uncertainty and confusion that emerged for non-specific LBP in this analysis compared to the other labels might partially justify clinician reluctance to use this term. For patients, there can often be a pressure to get a diagnosis to legitimise their pain [37, 38]—which can involve efforts to prove a structural source of their LBP. A vague diagnosis could also contribute to patient uncertainty, and patients may feel they are not believed. These pressures could act as a barrier to the uptake of labels such as non-specific LBP and episode of back pain, and potentially leave people vulnerable to receiving labels that drive poor care and outcomes. Pain management focusing on legitimising people who live in pain could be helpful in allowing people to live valid lives. It would therefore be important to examine both patients’ and wider systems (e.g. workplaces, insurance companies) desire for updating diagnostic labels, their understanding of the causes of LBP, and explore how labels associated with a positive prognosis can be successfully communicated across various contexts.

Conclusion

Poor prognostic outcomes were frequently evoked among participants in the disc bulge, degeneration, and arthritis groups, while beliefs of good prognostic outcomes emerged for lumbar sprain, non-specific LBP, and episode of back pain. Non-specific LBP produced feelings of uncertainty. Surgery was a more common treatment choice for disc bulge, degeneration, and arthritis, compared with lumbar sprain, non-specific LBP and episode of back pain. Surgery was not suggested for non-specific LBP and episode of back pain. Our results suggest that clinicians should consider avoiding the labels disc bulge, degeneration and arthritis and opt for labels that are associated with more positive beliefs about prognosis and less preference for surgery when communicating with patients with LBP. Future research should examine broader systems openness to updating diagnostic approaches for LBP to ensure that individuals with LBP do not receive labels that have negative impacts.