This blog has been inspired by a study performed by my colleagues at the Pain Clinic of the University of Washington Drs. Sturgeon, Langford, Tauben, and Sullivan: Pain Intensity as a Lagging Indicator of Patient Improvement: Longitudinal Relationships With Sleep, Psychiatric Distress, and Function in Multidisciplinary Care.
"If my pain is reduced, my sleep, mood, and physical function will improve".
This is a frequent assumption not only by patients, but also by health care professionals. The expectation that reduction of pain will improve the putative consequences of pain, such sleep disruption or inability to accomplish daily activities, seems reasonable and is also supported by some evidence: treatments that reduce substantially the pain can secondarily lead to improvement in other domains (see here).
However, substantial pain reduction is infrequent
Not uncommonly, treatments that primarily aim to reduce pain, such as medications and procedures, are either not indicated, have been only minimally effective, or have not been effective at all. In such situations, focusing on the treatment of co-morbidities, such as sleep, mood disorder, and physical function, may not seem straightforward to patients. Rather, patients and health care professionals may continue to "try" different ways to reduce pain intensity, such as performing procedures or surgery, even if the chance of success is very low. This is mostly because of the assumed unidirectional relationship between pain and co-morbidities, the latter being the consequence of the pain. However, this assumption has been challenged by several studies that have shown bi-directionality of the relationship.
Pain may also be the consequence of co-morbidities
For instance, sleep disorder is associated with dysfunction in pain modulation, and there is evidence that sleep disorder is a strong predictor of pain (see here). Similar associations with pain can be found for depression, anxiety, post-traumatic stress disorder, and physical deconditioning, among others. While association studies cannot establish causality, it is likely that co-morbidities such has insomnia, physical disability and psychological disorders contribute to pain perception.
The study by my colleagues Sturgeon, Langford, Tauben and Sullivan has analyzed 666 patients who had a reduction in pain intensity of at least 1(0-10 scale) over one year. They found that improvement in sleep, depressive and anxious symptoms, and disability predicted later improvement in pain intensity.
Trying first to reduce the pain is not an appropriate approach
Pursuing pain reduction with medication and procedures while leaving co-morbidities untreated is not associated with the best chances of success. A multimodal approach that addresses pain, psychological and physical functioning is standard of care for chronic pain. In the presence of severe psychological disorders, it may even be appropriate to treat first these disorders before offering a procedure. There is indeed evidence that patients with psychosocial distress are less likely to improve after a procedure, or may experience shorter-lasting pain relief (learn more here).
Take-home messages
Treatment of sleep disorder, psychological distress and disability may promote pain reduction.
At best, these treatments have to be initiated in association with therapies that aim to reduce primarily pain intensity, such as analgesics and procedures, rather than after analgesics and procedures have failed to provide pain relief.
Reduction in psychosocial distress may improve the chances of success of procedures.
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