Evolving Attitudes Toward Numeric Pain Assessment Among Patients with Hypermobile Ehlers-Danlos Syndrome: A Qualitative Interview Study

Dear Editor,

Hypermobile Ehlers-Danlos Syndrome (hEDS) is the most common of the 13 types of Ehlers-Danlos syndrome [1]. Among its primary features are joint hypermobility, fatigue, and chronic pain. There is still no known genotype associated with hEDS, meaning that clinicians must rely on a rigid set of clinical criteria to make an accurate diagnosis [2]. These criteria include self-reported chronic pain, which makes the assessment of pain central not only to the experience of hEDS but also to its diagnosis. However, the elicitation of pain scores is irreducibly subjective and private. Thus, an understanding of the beliefs and practices of patients in quantifying their pain is essential to the successful management of hEDS and other conditions characterized by chronic pain.

The 11-point numeric rating scale (NRS) is the instrument most commonly used to determine patients’ perceptions of their pain. Clinicians ask patients to rate their pain on a scale of 0 (no pain) to 10 (the worst pain imaginable). On the basis of this self-report and a physical examination, clinicians take actions to moderate patients’ pain. The NRS is also subsequently used to evaluate the success of those pain management techniques in follow-up appointments.

Many studies have experimentally determined that patients’ use of the NRS is adequate [3, 4], and it has been shown to be better at representing pain intensity than other measures [5]. However, consistency in the use of the NRS is a significant problem for many patient populations, including those suffering from chronic pain [6]. A better understanding of the use of numeric pain assessment instruments could therefore improve how we care for these patients. To that end, we conducted in-depth, qualitative interviews with 35 patients diagnosed with hEDS to elicit and characterize the thought processes behind their use of these instruments.

Methods

Participants and Procedures

Our study was approved by the Indiana University Institutional Review Board and ran from January 2020 until September 2021. All participants provided informed consent. Candidates were at least 18 years of age, had a clinical diagnosis of hEDS, and spoke English. They were recruited from the Indiana University Ehlers-Danlos Clinic, a major site for the diagnosis and care of this patient population. All participants completed an initial, broad interview about their experience pursuing a diagnosis, in which the issue of pain assessment was discussed. A subset of these participants was contacted to complete a second interview in which pain assessment was explored in greater detail. Participants in the second round of interviews were selected from the first population via purposive sampling to maximize diversity of backgrounds. Recruitment was considered sufficient once thematic saturation was achieved [7].

Interviews

The first interview guide included a section on the assessment and communication of chronic pain. For instance, patients were asked how successfully chronic pain could be measured and how its measurement was similar to and different from that of other symptoms. More detailed information about those interviews is available elsewhere [8]. In the pain-specific interviews, participants were asked to describe their thought process in determining a numeric rating of their pain and whether it had changed over time. Both interview guides are available upon request. All interviews were audio-recorded and professionally transcribed. We conducted thematic analysis to investigate qualitative aspects of the interviews systematically [9].

Results

Sample Description

Thirty-five participants completed the initial round of interviews; fifteen of those individuals additionally completed the pain-specific interviews. All participants reported chronic pain as a primary complaint related to their diagnosis of hEDS. Table 1 summarizes participant characteristics. Interviews lasted an average of 58 minutes. Identifiable information has been removed, and each participant has been assigned a unique number, presented in parentheses after quotations.

Table 1.

Demographics

	First Interview	Pain-Specific Interview
	(n = 35)	(n = 15)
Age, n (%)
18–29 years	11 (31)	4 (27)
30–39 years	10 (29)	4 (27)
40–49 years	8 (23)	4 (27)
50–59 years	5 (14)	2 (13)
60+ years	1 (3)	1 (7)
Gender, n (%)
Female	20 (59)	14 (93)
Male	1 (3)	1 (7)
Nonbinary	4 (12)	0 (0)
Race and ethnicity, n (%)
White	30 (82)	12 (80)
Black or African American	1 (3)	1 (7)
Multiracial	2 (6)	2 (13)
Educational attainment, n (%)
High school	3 (9)	2 (13)
Some college or an Associate’s degree	10 (29)	3 (20)
Bachelor’s degree	12 (34)	7 (47)
Graduate degree	9 (26)	3 (20)
Employment status, n (%)
Full time	12 (34)	5 (33)
Part time	1 (3)	0 (0)
Student	4 (11)	2 (13)
Unemployed/disability	17 (49)	8 (53)

Learning How to Use the NRS More Accurately

In the interviews, participants described using the NRS inconsistently across encounters and over a lifetime, making the calibration of individually expressed numbers impossible. Many participants described a “learning curve” in figuring out how to describe their pain successfully to clinicians using the NRS. One interviewee said that “the pain scale in my head has just gotten more clear” (119) because of the frequency with which she is asked to rate her pain. For these patients, their use of the NRS was inconsistent over time because they were slowly learning which numbers to assign to different amounts or qualities of pain.

Evolving Attitudes Toward and Experience of Pain Stimuli

Other interviewees described a shift not in their understanding of the scale, but rather in their understanding of pain itself. They regularly mentioned that this was a necessary result of living with chronic pain. “As a teenager, I’d have a stiff neck and wouldn’t feel well, and thought it was really bad” (116), one woman explained. For these individuals, their shift in perspectives was tied to concrete events, such as brain surgery or developing kidney stones. “Before childbirth, I didn’t have an example of very, very uncomfortable pain” (120), another interviewee explained, indicating that this experience had transformed her use of the NRS.

Discussion

A novel finding of our study is that participants described changing attitudes toward pain and its quantification over their lifetimes. They underwent a self-education as to what standards or benchmarks they assigned to different numbers, for instance, with the experience of painful surgeries or births. They also experienced an evolution in their perception of pain in the form of acclimation and tolerance. However, these developments did not necessarily make the use of the NRS easier for them, as they struggled to understand whether changes in their perception of the acceptability of different levels of pain should affect their ascription of a particular number to that pain. Our study highlights the need for clinicians to practice caution when using the NRS to assess pain and pain management in hEDS and other conditions characterized by chronic pain. Caution is critical, as such ratings across patients or even across visits are clearly not reliable on their own. More contextual and qualitative information is necessary to interpret these speciously quantitative data.

Limitations

This study has several limitations. The sample was largely White and predominantly female. Although this is appropriately representative of the demographic breakdown of the hEDS population as a whole, it also suggests a potential limitation in the breadth of perspectives captured in our study. This might be particularly true as research has found significantly different experiences of clinical management of chronic pain among Black patients [10].

 

Funding sources: This work was supported by the Indiana Clinical and Translational Sciences Institute (IU Grand Challenges Program) and the Precision Health Initiative at Indiana University.

Conflicts of interest: The authors have no conflicts of interest to declare.