Pain medication management of musculoskeletal conditions at first presentation in primary care: analysis of routinely collected medical record data

Guidelines for the management of painful musculoskeletal conditions advocate a holistic approach incorporating education, psychological, physical, and surgical interventions administered in a step-wise fashion [1, 2]. This comprehensive strategy is, however, underpinned by the use of analgesic medications which play a central role in the management of musculoskeletal conditions [3]. In addition, musculoskeletal pain has financial consequences for both the patients and their employers in terms of sickness absence and lost productivity [4]. For example, the direct health care cost of back pain in the UK in 1998 was estimated to be around £1.6 billion with the cost of informal care and productivity losses related to back pain totalling £10 billion [4]. Currently, there is evidence that analgesic management still needs considerable improvement [5] and consequently, a better understanding of analgesic use is essential if we are to improve this element of musculoskeletal pain management.

In 2003, the World Health Organisation (WHO) offered health care professionals guidance on the use of analgesia in low back pain that is equally applicable to musculoskeletal conditions in general [1]. This advice constituted an analgesic ladder, whereby doctors were encouraged to use basic analgesics in the first instance (e.g. paracetamol), then step up to using non-steroidal anti-inflammatories if basic analgesics did not control the pain, and where appropriate as a third step, use opioid analgesics such as codeine. The WHO guidance is explicit in its use of opioids as a third line treatment because of concerns relating to the risks of addiction. This advice has been widely disseminated and is also currently reflected in the NICE guidelines for managing osteoarthritis [2].

Despite guidance advocating similar approaches for neck and low back pain, their management strategies have been shown to be different in terms of the analgesics prescribed and other therapies [6]. Whilst even with the introduction of guidelines, analgesic prescribing in patients with low back pain has not been shown to change [7]. Other influences than guidelines may affect a GP’s decision making, for example GPs may feel a more potent analgesic in the first instance is more appropriate than basic analgesics if the patient presents with severe and debilitating pain despite risk of side effects. The extent and type of analgesic prescribing in new episodes of musculoskeletal pain is unclear, as is how it varies by site of problem (for example, knee, hip, back), or whether there are characteristics of the patient which are associated with the decision to prescribe analgesia and the type of analgesia prescribed.

The primary objectives of this study were therefore, to describe the analgesics that primary care clinicians prescribe when a patient consults with a new episode of a musculoskeletal condition, and to determine socio-demographic and clinical factors associated with being prescribed medication and type of medication.

This study has shown that more than half the patients consulting for a new episode of a musculoskeletal condition were not prescribed pain medication. Of those who were, most commonly NSAIDs were prescribed, with basic analgesics being the second most common analgesic. There appears to be restricted early use of stronger medication with strong opioids being prescribed for only one in ten new musculoskeletal patients prescribed pain medication. Patient age, deprivation, body region of pain, comorbidity and previous analgesic prescriptions were associated with prescribing behaviour and there was extensive practice variation.

Our study found less than half of new consulters for musculoskeletal pain received an analgesic. A previous study of those aged over 50 consulting in primary care for musculoskeletal pain, and who had not consulted in the previous 30 days, also reported that less than half were prescribed analgesics [17] and this is also similar to findings from studies focussed on neck and back pain [6, 7] and on osteoarthritis [18]. It is feasible that GPs may be following guidelines that recommend the early use of exercise and other physical therapies with or without analgesia and further research is needed to determine if this is happening [1, 19].

The WHO advice relating to managing low back pain, one of the commonest forms of musculoskeletal pain treated in primary care [1], suggested that clinicians should administer simple analgesics like paracetamol for pain relief prior to considering using oral NSAIDs, and then opioids if pain is not controlled by the previous analgesic group. Basic analgesics are available over the counter without prescription, and patients first seen in primary care may already be using these medications. Prescribing of NSAIDs may reflect clinicians feeling that the severity of their patients’ complaints warrants an analgesic stronger than that available without prescription. If a basic analgesic has already been used, the next step in the WHO analgesic ladder is to use NSAIDs, followed by weak opioids and subsequently stronger ones. In our study the most potent opioid medications were indeed prescribed less than basic analgesics on first consultation. This may also reflect other elements of the clinician’s decision making process, which takes into account the adverse side effects that patients are more likely to experience when prescribed higher potency drugs. Starting at a lower potency minimises this risk [16, 20, 21]. Rather than a patient’s previous consultation history for musculoskeletal conditions, it appeared that the clinician’s knowledge of previous analgesic medication affected their prescribing. A patient with a past history of prescribed pain medication was more likely to receive any analgesic and, particularly, stronger analgesic, as has been shown previously [17]. Clinicians will generally ask the patient about their medication use prior to consultation [20]. The more potent analgesic may subsequently be used if the patient’s experience of pain relief with the previous basic analgesic was unsatisfactory.

Clinicians appear to consider patient age when choosing to prescribe a pain medication or not, and what level of analgesic potency to prescribe. In our study, those aged over 75 were twice as likely to receive pain medication as younger age groups, but were less likely to be prescribed NSAIDs. This finding is in keeping with current advice on NSAID use in older patients who might be considered more likely to experience adverse effects such as renal toxicity [16, 22] and gastrointestinal haemorrhage [23, 24] with NSAIDs. Stronger opioids were less likely to be used in those aged over 75, a finding that has also been described previously [25–28]. This would make clinical sense since using these more potent opioid type drugs in the elderly has been associated with increased rates of falls and bone fractures [21]. Comorbidity was linked to a lower likelihood of being prescribed NSAIDs which also reflects the possibility clinicians are avoiding these drugs in patients more vulnerable to side effects [29]. However, this finding was non-significant and the prevalence of our selected comorbidities in this group with new musculoskeletal problems was low. Further research is needed on the extent to which comorbidity influences analgesic prescribing.

Younger adults (15–29) were more likely to be prescribed basic analgesics, perhaps reflecting the less severe nature of pain in younger people with musculoskeletal problems [30]. Female patients were more likely to be prescribed weak or moderate opioids over basic analgesics. They also had a non-significant higher likelihood of receiving stronger analgesics. Females are often perceived as experiencing more pain than males and females have been shown to be better than males at communicating their pain [3, 20, 31, 32], which may influence the decision to prescribe more potent medication than basic analgesics.

Patients from the most deprived areas were more likely to be prescribed pain medication than patients from medium and least deprived areas and be prescribed stronger analgesics. Social characteristics such as neighbourhood level of deprivation have an additional effect on pain [33, 34]. The level of pain is associated with emotional distress, low social support and low social participation that may be more common in deprived areas [20, 33]. Further, patients in more deprived areas may rely on prescribed medication even for pain that can be eased with over the counter medications as prescriptions are free for low income and older patients in the UK [35]. Patients from least deprived areas may prefer to purchase over the counter medications as they pay for their prescriptions, a finding shown previously for over the counter use of aspirin in cardiovascular diseases [36].

Patients presenting with back problems were most likely to receive pain medication and to receive stronger analgesics. Back pain limits the functional reach of limbs and the ability to rotate the trunk repetitively which is essential for mobility, and results in restrictions on individuals’ social and physical activities and a substantial impact on their life style [32]. Clinicians may be more likely to perceive back pain as limiting in the day to day activities that a person has to perform hence consider there is a greater need to prescribe stronger pain medication for back pain. Additionally, clinicians’ perceptions of the handicap that pain causes may vary across different body regions. For example back, knee and hip pain may be perceived as being debilitating in terms of mobility, whilst shoulder, wrist and hand pain limit daily activities such as washing, cooking, and cleaning [15, 37, 38]. This may be reflected in some body locations being associated with prescription of more potent analgesics than others.

The findings of this study are limited by the fact that it was based in a regional dataset and therefore might not be reflective of analgesic prescribing in other areas of the United Kingdom. However, the data used in the study is drawn from a data set, CiPCA, which gave comparable consultation figures for musculoskeletal conditions as the larger national databases [8]. We did not evaluate the prescribing of pain medication by specific diagnoses. However, patients often present to primary care with a regional musculoskeletal symptom, such as back or knee pain, which is not initially labelled with a diagnosis. Region specific management is common in primary care, for example for back pain [1], and GPs may prefer to work with a regional pain label than a complex diagnostic label. Patients were selected over a 12 month consultation period and the inclusion criteria may include patients with musculoskeletal episodes with a periodicity more than 12 months and those who have been taking over the counter medications or receiving other care. Their previous consultation and medication prescription history may not be a true reflection of the starting point of the pharmacological management of a musculoskeletal condition. However the inclusion criteria ensures that it is reasonable to consider the patients as having no chronic pain prior to consulting as chronic pain is defined as pain lasting more than three months [5, 11]. Clinicians consider multiple factors in deciding the medication and appropriate dose [16, 20, 39, 40] and there may be other unmeasured variables such as other contraindications which may influence prescribing. Pain severity, weight, alcohol misuse and ethnicity might also impact on prescription of pain medication [41] and these are not evaluated in this analysis.

This study highlights that age, deprivation, body region of pain, comorbidity and previous analgesic prescriptions are associated with analgesic prescribing in primary care when treating patients with a new consulting episode of a musculoskeletal condition. There appears to be a clinically sensible use of these painkillers, in as much as analgesics such as NSAIDs and opioids are less likely to be used in groups that may be more vulnerable to potential side effects. Prescribing also varies depending upon the region of pain being treated. The prescribing characteristics may follow the WHO analgesic ladder of prescribing since there is a restricted use of stronger analgesics at first consultation. However, further research into the pharmacological management of musculoskeletal pain is required to determine if these patterns of prescribing represent the optimum management pathways when managing musculoskeletal conditions.