When researchers use randomised controlled trials as the way to investigate health interventions, it’s usual to clearly describe inclusion and exclusion criteria. This makes sure the participants all share the same characteristics so any effects from the experiment can be fairly evaluated. It wouldn’t be fair to have some people in the experimental group without the disease, or for them to have a different disease from the one targeted by the intervention.
This has led to many studies for painful conditions, particularly chronic pain, to exclude people with comorbid mental health problems for example. In a study looking at low back pain, people with pain in other parts of their body might be excluded.
Now while this makes perfect sense when we’re studying the effect of a single intervention on a single disease, it makes applying the findings to real people rather more difficult.
It’s more common than not for people to have several health problems going on at the same time. And especially as we get older, the health problems keep on coming. People with chronic pain are most certainly likely to have more than one health problem (Foley et al., 2021; Nakad et al., 2020), and the recent study I wrote about here found pain profiles linked less to specific disease and location than it did to other characteristics (Barron et al., 2024).
The practical implications (my ‘so what?’ question) are profound. If a specific therapy shows an impact on a specific disease and we’re clear about the causal mechanisms at play, perhaps we can immediately translate what’s found in research to clinical practice. BUT, in many cases in chronic pain, we’re talking about unknown causal relationships, interventions with impacts on multiple body systems (think exercise, for example), and we’re also talking about people who have more than one disease process going on. This means applying what’s learned in clinical trials, even very good ones, to this person with more than one health concern, is much more problematic – the results are likely to be uncertain.
The cumulative effect of health problems goes further than response to treatment. It also affects the impact of a disease process on a person’s illness experience. It’s harder to deal with the effects of, say, Covid, if you’re already experiencing a chronic respiratory disease. If you have irritable bowel disorder and develop diabetes, the ‘self management’ suggestions might not fit well for you because there are limits on how much exercise you can do and the foods you can eat.
Last year I had cataract surgery, and a few weeks before I had covid. While I was largely recovered from covid when I had my surgery, I had a bit of a cough. Today I still have that cough and I’ve had a complication from cataract surgery that’s affecting my central vision (macular oedema). On top of also having fibromyalgia with the usual body pain and fatigue. The cough gets worse when I’m fatigued. The eyes get worse when I’m fatigued. When both the cough and the eyes are playing up, AND I’m sore – well it’s a bit to deal with.
Why is it harder than if I just had the one thing? Well, I have to do a lot of problem-solving to work with my fatigue and pain. I need to use metacognitive skills to think about my thinking, do the planning, make adjustments to how and what I expect to do. This takes cognitive bandwidth. Now add a layer of ‘I can’t really see very well’ and everything I need to do just gets harder. More planning and problem-solving. More finding ways to get things done. More time needed to do the problem solving, try the possible solutions, get skilled at them, evaluate their effectiveness, rinse and repeat.
A practical example? I have a time crunch where I need to read documents, absorb them, then use that information. With my vision playing up, I could use text to speech. There’s a learning curve to doing this before it becomes both natural and effortless. In the meantime, I need to use more brain power to do the learning, leaving less available for other things I have to manage. I’m using energy to learn to use the text to speech approach and that energy is now not available to use in other parts of my life, like deciding what to have for dinner tonight.
Now RCTs might tell us what to do about long covid. Studies might tell us what to do about macular oedema. Studies might also tell us something about what ‘works’ for fibromyalgia. But it’s going to be a rare study that pulls together this unique combination for me – oh and add a dash of ADHD and my prediabetes to the mix!
What’s a clinician (and a person living with pain) to do? No, I don’t have The Solution because frankly I don’t think there is One Solution for All. My suggestions are these:
- Always ask about the other diagnoses a person has – but also ask about the impact of those diagnoses on living daily life. Consider the impact of making room for a problem on ‘life capacity’ elsewhere.
- Hold your adherence to RCTs lightly. Remember these studies aren’t representative of real people that you’re likely to see, and the results from interventions may not have the impact they seemed to have in the research studies. Statistical significance only tells you the two groups differed more than chance, it doesn’t tell you whether that difference is meaningful to the people involved. Seriously, folks, a reduction of 4mm on a 0 – 100mm visual analogue scale is not really going to make a big difference to quality of life even if it looks good statistically! Apply principles, perhaps, but specifics may not be relevant to individuals.
- Given RCTs don’t often answer questions about multiple morbidities, be aware that a solution that helps with one thing can create a problem with another. Even if the effect sizes are small, a small negative impact on another health condition can be profound in the overall scheme of things.
- Sometimes symptoms can be linked to something else. My fatigue and cough and my macular oedema could be linked to long covid, rather than being separate things. Treating each symptom independently might lead to an overall change, but maybe it’s worth looking at whether there is another problem – perhaps in my case it’s an over-enthusiastic immune system (not uncommon for me anyway!). Perhaps treating my immune system over-sensitivity could help resolve all of these things? Who would know (covid being still pretty darned weird).
- While someone is dealing with a new problem, it’s probable they have less capacity for things like problem-solving, learning, changing routines, adding new things to daily life. It might take longer for them to learn techniques, to change habits, or to come up with solutions. And meanwhile life activities continue. Don’t expect people to set goals across multiple areas of life because it’s going to be too hard – this is why interprofessional teamwork is important, rather than multidisciplinary teamwork. Goals and actions need to be integrated so the person doesn’t see three clinicians and get six sets of ‘goals’ to achieve – on top of just keeping daily life going.
- On their own, each problem may not look severe. But together? Another story. Keep listening. Keep asking about the person’s ‘main concern.’ Listen to the answers. Titrate the actions you think the person ‘should’ do in light of both their actual capacity to do things, AND their main concern. If what you’re suggesting doesn’t address their main concern it might not get done. If what you’re suggesting exceeds what they can manage, it might not get done. Be pragmatic. A start is a start. It’s easier to change when moving, than to start. Progress is progress. Be kind and understand that a person’s priorities might not be their health – it could be something else, like their relationship or their garden.
Healthcare is not a simple game. It’s complex and full of ambiguity. Clinicians focus on their piece of the puzzle, but the big picture isn’t visible. It’s often not fully visible to the person asking for help. Big pictures develop when we collaborate, clinicians and people seeking help and their communities. Health is multicoloured not black and white.
Barron, D. S., Saltoun, K., Kiesow, H., Fu, M., Cohen-Tanugi, J., Geha, P., Scheinost, D., Isaac, Z., Silbersweig, D., & Bzdok, D. (2024). Pain can’t be carved at the joints: defining function-based pain profiles and their relevance to chronic disease management in healthcare delivery design. BMC Medicine, 22(1), 594. https://doi.org/10.1186/s12916-024-03807-z
Foley, H. E., Knight, J. C., Ploughman, M., Asghari, S., & Audas, R. (2021). Association of chronic pain with comorbidities and health care utilization: a retrospective cohort study using health administrative data. Pain, 162(11), 2737-2749. https://doi.org/10.1097/j.pain.0000000000002264
Nakad, L., Booker, S., Gilbertson-White, S., Shaw, C., Chi, N.-C., & Herr, K. (2020). Pain and Multimorbidity in Late Life. Current Epidemiology Reports, 7(1), 1-8. https://doi.org/10.1007/s40471-020-00225-6