To explore the pain experience of persons with chronic pain of the hip or knee in the context of self-assessment instruments commonly used to assess pain severity in individuals with osteoarthritis.
To explore the pain experience of persons with chronic pain of the hip or knee in the context of self-assessment instruments commonly used to assess pain severity in individuals with osteoarthritis.
Participants who reported that they currently had either hip or knee pain were recruited from the UK Somerset and Avon Survey of Health. A total of 28 participants (14 men and 14 women, ages 57–89 years) took part in 6 focus groups stratified according to pain site and severity. Using the “questerviews” technique, participants described and discussed their experience of joint pain in the context of standard self-assessment questionnaires: the Hip Disability and Osteoarthritis Outcome Score and the Knee Injury and Osteoarthritis Outcome Score. The focus groups were audio recorded and transcribed. Data were analyzed by identifying emergent codes that were grouped and compared, resulting in the identification of key categories.
Both knee pain and hip pain participants expressed similar pain experiences. Four key categories were identified, all of which impacted upon participants' responses to the standardized questionnaires: pain is intermittent and variable, pain elsewhere in the body influences the experience of joint pain, pain is inextricable from function, and adaptation and avoidance strategies modify the experience of pain.
The assessment or measurement of pain should take into account the importance of pain experience as well as severity through use of patient narrative accounts.
Pain is the dominant symptom for most individuals described in clinical practice as having musculoskeletal conditions such as osteoarthritis (OA) (1, 2). Much time and effort have been put into the development of disease-specific self-assessment measures of health status in rheumatology. Pain assessment is a key component of all such measures. It is usually assessed as current pain severity on a Likert scale or a visual analog scale, sometimes differentiating rest pain from activity-related pain or night pain. Pain severity assessed in this manner is often used to aid decision making about the utilization of major interventions for patients with chronic joint pain, such as the suitability of joint replacement (3).
Little research has been conducted on the experience of chronic joint pain, despite recent recognition of the complexity of pain perception. As part of an international initiative designed to help define severity states in OA, we conducted focus groups with individuals who have chronic pain of the hip or knee to explore their pain experience. Persons with chronic hip or knee pain would normally be defined in clinical practice as having OA. To assess the suitability of standard outcome measures that assess pain in OA, we used the “questerviews” technique (4) as part of our focus groups, allowing participants to relate their pain experience to the questions used to assess pain severity as part of those measures. Exploring participants' experiences also enables us to monitor the efficacy of interventions using standard disease-specific self-assessment questionnaires, many of which are used to aid clinical decision making (see Participants and Methods).
This study was approved by the UK South-West Multi-Centre Research Ethics Committee (approval number MREC/01/6/51, amendment version 2). We used qualitative methods because they enable the exploration of experience and meaning (5). Focus group techniques were used because they allow participants' experiences to be elicited in the context of discussion as participants query and clarify one another's statements and opinions (6). Participants were selected from the Somerset and Avon Survey of Health (SASH) (7) if they had reported current hip or knee pain at the followup survey, which included 1,113 individuals in 2002–2003. A total of 81 potential participants were invited to take part and 28 attended. Most nonattendance was due to inability to attend a group at the prespecified time.
The groups were stratified by pain severity assessed at the SASH followup survey in response to the question: “Please think about the pain in general that you have had in or around your hips or knees, over the past 12 months, even if you have been taking tablets or other forms of medication, e.g., injections.” Survey participants were asked to rate their pain on a scale from 1 to 10, where 1 represented “no pain” and 10 represented “pain as bad as it could be.” Participants were grouped according to whether they said they had mild pain (score 2–4), moderate pain (score 5–7), or severe pain (score 8–10), and by joint site affected (hip or knee), resulting in 6 different groups of 3–6 participants (Table 1).
|Focus group and participant identification||Age, years||Sex||Highest hip or knee pain score at survey|
|Focus group 1: mild knee pain|
|Focus group 2: moderate knee pain|
|Focus group 3: severe knee pain|
|Focus group 4: mild hip pain|
|Focus group 5: moderate hip pain|
|Focus group 6: severe hip pain|
An experienced researcher (GW) facilitated the groups using the questerviews technique (4) to lead the participants through completion of the standard self-assessment questionnaires, the Hip Disability and Osteoarthritis Outcome Score (HOOS) (8) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) (9). These questionnaires are widely used and validated instruments that incorporate the whole of the popular Western Ontario and McMaster Universities Osteoarthritis Index (10). Subscales within the HOOS and KOOS address pain, stiffness, activities of daily living, sporting activities, and quality of life. The questerviews technique involves using questionnaire items to elicit rich narrative about health experiences; it is not intended as a validation strategy. In the focus groups, each participant was provided with a copy of the HOOS or KOOS. The facilitator asked participants to describe and discuss their thoughts when completing the questionnaire, particularly focusing on pain items and issues requiring clarification. The groups were asked to discuss their responses at the end of each section, leading to general discussion about their pain experience.
The focus groups were audio recorded and transcribed. A scribe was present during focus groups to note the first words of each statement; this maintains accuracy in transcribing. The focus groups were analyzed independently by 2 experienced qualitative researchers (RG-H and GW). Using methods of constant comparison (11), the researchers each assigned codes to the data and then grouped these into categories. The coding schemes of each researcher were compared with one another and a consensus was achieved, thereby identifying several key categories. Because the categories emerged inductively from the data, they do not necessarily correspond with the questionnaire subscales.
A total of 14 men and 14 women (ages 57–89 years, mean age 70.8 years) took part in focus groups that lasted between 90 and 120 minutes. Both the knee pain and the hip pain groups expressed similar experiences of pain, concerns, and behavior. Pain severity did not appear to influence the presence or absence of their experiences. Four key categories regarding the experience of pain were identified, each described in turn: pain is intermittent and variable, pain elsewhere in the body influences the experience of joint pain, pain is inextricable from function, and adaptation and avoidance strategies reflect those experiences.
Both hip and knee pain were intermittent and variable. Participants described their pain as changing month by month, day by day, and by the time of day. Both hip and knee groups expressed these changes. For example: “It is difficult to answer that for me as well, because I never know, I could go months without any pain. Another time I could get pain every week you know” (participant K.3, man, mild knee pain group); “It does vary week to week. … It tends to go in cycles, the problems, and, you know, you either get a good week or a bad week” (participant H.16, man, mild hip pain group); “And mine is mostly in the mornings, when I first get out of bed it's really bad” (participant K.2, woman, mild knee pain group).
Among those who had less pain overall, the pain was often described as occurring occasionally or as “twinges”: “Well I've had pain in my left knee since I was carrying my boy, that would be 41 years ago, and I fell off a bus. But it's only been, I mean it was bad then, but just now and again I get a sort of twinge in it, but nothing, no not every day or anything like that” (participant K.1, woman, mild knee pain group). More unusually, one participant described how her pain was constant and did not vary much over time: “I got [pain] nearly all the time there” (participant K.7, woman, moderate knee pain group). Others described the constant presence of pain, but emphasized that their pain was also exacerbated by activities: “I think … to me the pain is always moderate, apart from some things that you do, like going upstairs, or if you twist or anything like that … it's quite different” (participant K.11, woman, severe knee pain group).
The moderate hip pain group discussed the role of psychological influences on the presence or absence of pain:
Participant H.24: “And you think, ‘I’m going to do it, whatever.' And the next minute you're home sitting on your own, and you think, ‘Oh it’s coming back again.' It's quite illogical, a lot of it” (woman, moderate hip pain group).
Participant H.21: “Something horrible happens sometimes, and you've got to deal with it, you know, something perhaps in the family, someone's ill or something, and you forget, you really do” (woman, moderate hip pain group).
Participant H.25: “Mind over matter” (woman, moderate hip pain group).
Participants had difficulty conceptualizing knee or hip pain as separate from pains in other parts of the body. This was either because they thought that they had referred pain, because other parts of their body presented greater problems, or because they had been told that pain elsewhere was not pain in the joint. In the mild knee pain group, one woman described how pain elsewhere had been more of a problem than her knee:
Participant K.2: “And the pain in my hands, in my feet, back, I've had for about 10 years. But the pain has got worse.”
GW: “And in your knee?”
Participant K.2: “No it's just like a slight pain I get now and again, but nothing that I would complain, you know, go to the doctor about” (woman, mild knee pain group).
In the moderate knee pain group, one man discussed how the pain in his ankle developed following knee replacement surgery: “Yes I know, but what I'm saying is that what happens to the ankle dictates what happens to the knee, or can do” (participant K.6, man, moderate knee pain group). Participants also described how pain did not stay static, for instance, moving between the back and hip: “Because sometimes it's like right in the middle of my back, but then another time you get it in one hip, literally as if someone has kicked you … it's really difficult to move” (participant H.14, man, mild hip pain group).
Among the hip pain groups there was evidence that participants found it difficult to differentiate between hip and knee sensations. Describing how he answered a questionnaire item about stiffness, one participant explained: “I just thought well I wasn't quite sure what you meant by joint stiffness. And after waking, and again after bed I can hardly walk, but I don't know whether it's to do with the knees or to do with my hips. So I've put ‘none’ ” (participant H.15, man, mild hip pain group). Occasionally the difficulty in separating one part of the body from another was reinforced by health care providers' opinions: “I suppose when I stopped teaching in ‘85 I started getting a lot of aching in my hips. And that went on for a very long time. And then they [health care providers] decided that it wasn’t my hips, it was my back, lower back. And they are still saying that, although I'm getting a lot of pain in one of my hips now. And a friend of mine said, ‘Watch that,’ she said, ‘they told me that for years and years, and when I had my hips done they said they were very bad’ ” (participant H.23, woman, moderate hip pain group).
All focus groups discussed the relationship between pain and movement, activity, or position. There was considerable awareness of the association, as participants believed this affected their daily lives significantly. The interaction between pain and function affected participants' ease in answering questionnaire items about pain. There were 3 key elements to this: pain affected by physical position, pain triggered or exacerbated by certain physical movements, and pain that was related to activities that entailed difficult positions or movements.
Participants in both the knee and hip pain groups highlighted the difference between sitting and lying in bed and the impact of sleeping arrangements on their pain. In the moderate hip pain group, participants discussed the importance of the type of bed, although there was no consensus about whether it was the bed or pain that really was at the root of sleepless nights and consequent pain: “I'm only like that if I'm on holiday. If I'm in my own bed I'm fine. But I find if I'm on a normal mattress, unless it's really, really soft, if I get in a hard bed I'm crippled, I can't get up, I've literally got to roll out of the bed and it's really bad. Even if I go to give blood, and I lay on one of their hard beds, I can't get up afterwards” (participant H.14, man, mild hip pain group).
Sitting for long periods also caused problems for participants in both the knee pain and the hip pain groups. In the mild hip pain group, participants discussed difficulty driving and sitting: “I find that, after driving some distance my leg gets pretty stiff” (participant H.18, man, mild hip pain group); “Even sitting down for a while, you know, I sit on a beanbag or lie on the floor just to change the position. And I do find vertical being far better than lying down” (participant H.16, man, mild hip pain group). Stiffness also varied according to whether participants were sitting or lying, which meant that participants had difficulty answering a question asking about sitting and lying down within one item: “That's a bit difficult really because I'm stiff sat down but laid down is easier you know what I mean” (participant H.26, man, severe hip pain group).
Although physical position was an important factor in the experience of pain and stiffness, groups also highlighted the interaction between position and movement. It was not merely that sitting was a problem in itself: transition between a stationary and a mobile state triggered pain. This was highlighted in every group, but especially in the mild hip pain group, which discussed this issue at some length: “A lot depends on how you sit, like sitting in a chair, and when you get up your back can—but then it goes when you start moving” (participant H. 17, man, mild hip pain group). And later on in the same group:
GW: “Is there anything else that people have highlighted there as problematic? So there's the ‘sitting and lying’—are they the same sorts of pain?”
Participant H.16: “It's the transition rather than the actual—it's the changing from one to the other is my problem. I can stay in the same position all the time and not experience pain, but even going from sitting to standing, lying to sitting, and whatever, it's the transition that gets me” (man, mild hip pain group).
Participant H.18: “Well if you're lying or sitting you can move your legs a bit, can't you. But coming back to driving a car, when you're driving a car, you know, your legs have to stay in the same position, and that's when I get the most stiffness” (man, mild hip pain group).
Participants were aware of the role of position and movement in their pain, and used their activities as a means to describe this role. The HOOS and KOOS contain a section about everyday activities (function) as well as recreation and sport; therefore discussion of this subject was instigated. However, participants also talked about activities such as sports or shopping without being prompted: “I suppose it started with—well I discovered it [knee pain] at around about 10 years ago—well it was probably just before that. And as I say, it's only at certain … activities” (participant K.4, woman, mild knee pain group). Participants also discussed how different activities entailed similar movements, so there was overlap between categories. For instance, in the severe knee pain group one woman (participant K.12) pointed out that shopping and walking were one and the same for her because going shopping necessitated walking.
In the moderate hip pain group, one participant described how his pain had improved greatly since the followup survey at which he had scored his hip pain as level 7. Since then he had given up football, which he thought was the reason for the improvement in his pain:
Participant H.24: “Well you're better, you see. You've improved since the last one [the SASH followup survey]” (woman, moderate hip pain group).
Participant H.20: “Well I don't think I was bad, I didn't have it sort of bad in the first place. So, you know, I don't think I” (man, moderate hip pain group).
GW: “I mean we will be asking you about why you think it might have improved, the hip and your pain, so”
Participant H.20: “Well probably because I stopped playing football, you know.”
Although activities were described in terms of triggering or exacerbating pain, they were also commonly discussed in terms of avoidance or adaptation. For example, it was commonplace for participants to describe how they avoided movement to avoid pain: “I don't bend the knee, because I know it's going to hurt me if I do. So I don't do it” (participant K.3, woman, mild knee pain group). Participants described the activities that they avoided. In the severe knee group, 2 women discussed domestic chores: “It's like heavy domestic duties, you know, well I wouldn't do it” (participant K.13, woman, severe knee pain group).
Avoidance of particular activities had ramifications for the ways in which participants completed the HOOS or KOOS questionnaires. For instance, if participants did not perform particular activities then they were reluctant to complete the relevant HOOS or KOOS item. Some participants completed the questionnaire by indicating that they had no difficulty with an activity because it was not something that they did. Although these anomalies mean the presence of missing or incorrect data, in this context they prove interesting as a discussion of avoidance of activities. In the moderate knee pain group, women discussed an item regarding scrubbing floors:
Participant K.8: “I shall ignore that” (woman, moderate knee pain group).
GW: “Which one are you going to ignore?”
Participant K.8: “A16—scrubbing floor business.”
Participant K.7: “I put ‘no’ ” (woman, moderate knee pain group).
Participant K.8: “Anything domestic, I don't do it. I could never do it.”
GW: “So what would you put down?” Participant K.8: “Well I don't do any of it, so how can you answer it really?”
Participants in all groups discussed the adaptations that they made, sometimes in general terms:
Participant K.11: “I think when you've got knee problems, you know, you come to compromise” (woman, severe knee pain group).
Participant K.13: “I mean you adapt your life” (woman, severe knee pain group).
Participant K.11: “Yeah.”
Participant K.13: “Find the easy way out.”
More generally, participants had altered their houses and their activities to accommodate their difficulties. Basic changes such as sitting in the front rather then the rear seat of the car became everyday preferences: “You know, like if I go out with my granddaughter, I can't sit in the back, I've got to get in the front” (participant K.7, woman, moderate knee pain group).
The experiences contained within the 4 categories influenced one another. The intermittent and variable nature of pain and the presence of pain elsewhere made predication of joint pain difficult. However, because the connection of pain with function was clear to participants, they were proactive in their strategies and were able to avoid and adapt their activities in spite of fluctuations in pain.
A series of focus groups with individuals with varying levels of chronic joint pain led to the emergence of 4 themes related to their pain experience: the intermittent and variable nature of the pain, the importance of pain at other sites in the body, the inextricable link between pain and activity, and the importance of strategies to avoid or adapt to the pain. These themes, coupled with the obvious difficulty that many participants had in answering the questions about pain severity used in the HOOS and KOOS self-assessment instruments, suggest that simple measures of pain severity used to inform clinical decisions and the outcomes of clinical trials provide too simple a view of the pain experience of most patients, and in some cases result in potentially misleading data on pain. The interaction between the key categories may prove to be central to understanding the nature of joint pain in a way that reflects the whole-person experience of pain.
It has been demonstrated before that chronic joint pain varies according to the time of day as well as other time-related variations, and it is well known that this may affect pain measurement (12). However, some participants reported a different type of variation such as pain coming in sudden short-lasting attacks or “twinges” and others reported relatively long periods in which they were pain free followed by periods of significant pain.
Recent research has shown that many patients with chronic hip or knee pain also have pain in other joint sites (13). Our data suggest that these other painful sites can have an important influence on a person's self assessment of their pain. The interrelationships between pain and function are well appreciated (14, 15), but it is clear that this link also influences the way in which individuals deal with self-assessment questionnaires that try to achieve clear differentiation between these 2 domains. Our data also suggest that avoidance or adaptation strategies have a significant influence on self assessment of pain and function; several participants pointed out that they do not have pain in association with certain functions because they know that engaging in these activities will cause pain so they simply do not do them.
A strength of this study was that focus groups enabled participants to discuss and compare their experiences with one another, allowing them to clarify one another's descriptions. The use of the questerviews technique helped participants focus on targeted outcomes that are also usually measured in research and clinical practice. Using the HOOS and the KOOS in this way means that responses were constrained to an extent to preexisting categories contained within the questionnaires. However, a strength of the constant comparison method is the induction of experiential categories that are important to participants, which can be different from the categories of the questionnaire. This discrepancy highlights the importance of including patients' experiences of pain in assessments. A weakness of focus groups is that accounts provided by participants may be public accounts rather than private (16)—some of the more private aspects of living with pain might be obscured from view. Future research might include one-to-one in-depth interviews about the pain experience. Although it might be argued that the sample size of 28 was small, by qualitative standards it was adequate and appropriate because no new themes were emerging by the final group.
Clinicians already familiar with patients' reports of pain will be well aware of the complexity of their patients' experiences and difficulty of obtaining a simple assessment of pain severity. Patients' narratives of pain reflect aspects of the pain experience that perhaps go beyond those that may be captured by questionnaires or measures. Recent moves to include patient narratives in research and clinical settings have highlighted the importance of patients' stories in providing diagnosis and planning treatment (17). This does not imply that objective measures are irrelevant, but shows the value of patient narratives as part of the clinical assessment process, and the role of the clinician in listening to those experiences. Furthermore, the questerviews technique can be invaluable in allowing rapid elicitation of narratives alongside objective measures. One direction for future work might be to conduct a larger study to assess the feasibility of using the categories identified here for assessing pain in a clinical setting. We recommend further work to investigate how narrative data of the sort captured in this study might be incorporated into clinical assessments and outcome instruments used for chronic joint pain.
Dr. Gooberman-Hill had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study design. Gooberman-Hill, Williams, Dieppe.
Acquisition of data. Gooberman-Hill, Woolhead, MacKichan, Williams.
Analysis and interpretation of data. Gooberman-Hill, Woolhead, Dieppe.
Manuscript preparation. Gooberman-Hill, Woolhead, MacKichan, Ayis, Williams, Dieppe.
Statistical analysis. Woolhead, Ayis.
We are grateful to the 28 individuals who took part in the focus groups. We thank Catharine Elliott and Simone Angel for transcribing the audio recordings. We also thank Gillian Hawker of the OMERACT/OARSI pain states group (University of Toronto, Toronto, Canada) for her assistance with the study design.