Commentary
[Relatively good] long term outcomes for young people with ME/CFS
Katherine S Rowe, 2019
apologies that I haven't taken part in this thread - awful migrainesmeans screens are deadly (I read the paper in print, dictated wtih Dragon and a friend cleaned it up for me).
This is a large study providing solid evidence for good outcomes, including recovery, for young people with ME/CFS. Although the figure of 68% for recovery at 10 years may overstate the situation, the outcomes are much better than for adults.
About the study
The study covers 784 young people with ME/CFS treated at a specialist outpatient clinic in Melbourne, Australia.
The average age at onset was 14.6 and at follow-up it was 22.5 years. Ideally, each patient would have been followed up for the same length of time, but this was a retrospective study and all cases were followed up between January 2008 and June 2011, and the average follow-up time was eight years but with a wide range — from 1 to 21 years. This makes interpretation of the findings a bit more complicated.
Impressively, the study managed to follow up 82% of patients (641).
The study used fairly strict diagnostic criteria. Most patients were diagnosed with Fukuda with the additional requirement for PEM, unrefreshing sleep and cognitive difficulties. Some of the very early cases were diagnosed using the Holmes criteria, which are generally seen as stricter them Fukuda.
75% of patients were female and 80% of all patients had a definite onset following an infection, most commonly EBV. This might be an unusually high proportion of sudden-onset illness for young people.
Recovery rates
Overall, 46% of patients reported that they had recovered. However, recovery rates by total length of follow up is more revealing:
- up to 5 years: 30%
- 5 to 10 years: 54%
- 10 years or more: 68%
The figures indicate that recovery rates steadily increase over time. Patients followed up for more than 5 years had eventual recovery rates of 54% to 68%, but 29% of this group said they recovered within the first 5 years.
These recovery rates and generally good outcomes were supported by the proportion of all patients reporting working or studying full- or part-time:
- 63% full-time
- 24% part-time, more than half of the time
- 8% part-time, less than half of the time
- 5% not working or studying at all
66% had continued education after school, of whom 20% had worked or were working part-time while studying.
29% received disability support. The majority of these were studying (the government had a special scheme to help people with chronic illnesses continue their education) or working part-time.
Looking more closely at "recovery"
The study appears to have defined recovery as those people who answer the question "Duration of illness if recovered" (though another question asked, "Are you no longer suffering from CFS?").
Patients also scored themselves between 1 and 10 on an ME/CFS global functional scale created by the clinical team, where each score is defined by five factors: work/study, social life, recovery from physical exertion, stamina and symptoms (I like the scale).
A score of 10/10 means that the patient is working/studying full-time, able to have an active social life and has no problems at all. A score of 9/10 is similar but stamina is qualified by "more tired than would expect" and "manage well but need to pace".
However, a score of 8/10 is qualified by "needs occasional day to recover" and "with some symptoms and rarely feel refreshed".
While 10/10 sounds like a full recovery to me, and 9/10 might be described as a "good recovery", 8/10 sounds more like a good situation but not really "recovered". The average score for recovered patients was 9 , which breaks down as:
- 34% 10
- 36% 9
- 20% 8
- 10% 7 or less
See the graph
Figures 5 & 6 from the paper, with the horizontal axes aligned for clarity.
Patients reported that the functional score wasn't simply due to ME/CFS; some had illnesses they differentiated from ME/CFS, including depression and IBS, and others reported that they had small children and were sleep-deprived. The paper doesn’t say what proportion of scores below 9 could be explained by these non-ME/CFS reasons.
On the other hand, patients also commented that they weren't quite sure what normal function was any more, and parents "often scored [young people's functioning] one point lower", all of which suggests that some functional scores, and "recovery" rates, might not be quite as good as reported.
So there is some uncertainty about the true rate of recovery in this study, and, overall, it seems likely the true rate is below the recorded one. Is there a way to get a feel for how much lower? Perhaps only counting as recovered patients who also scored themselves 9 or 10 would give an estimate of the lower bound for recovery rates. Does this sound reasonable? The numbers below are for patients who say they recovered and scored themselves 9 or 10 on the mecfs functional scale (numbers in brackets are the full recovery rates, regardless of functional score).
- 21% (30%) up to 5 years follow-up
- 38% (54%) 5 to 10 years
- 48% (68%) 10 years and more
Overlap between "recovered" and "not recovered"
As the paper points out, there was considerable overlap between the functional scores of those who reported that they were recovered, and those who did not report recovery (see the figure). That overlap reinforces the idea that there is some "fuzziness" around the concept of recovery. However, while 70% of patients reporting recovery scored themselves at 9 or 10, only 1% of non-recovered patients reported such high scores.
The most common score amongst those not reporting recovery was 6/10, which corresponds to working or studying part-time, with limited social life, mild physical activity such as walking, continuous symptoms and the need to pace carefully.
Around 10% of all patients had a functional score of 4 or less. 4 equates to a “major impact on life”.
The relatively good outcomes in this study reflect those of an earlier and smaller
study by David Bell. This followed 35 patients for an average of 13 years. 37% of them reported recovery while 43% reported that that they were not completely recovered, but felt pretty well. 10% remained very ill.
Note that most patients in this earlier study had a gradual onset, unlike the sudden onset of most patients in the new study.
Other findings
Although the clinic had baseline data for around 60% of patients, no baseline factors, including depression, predicted the eventual outcome of the illness.
My comments here have focused on overall outcomes. However, the clinic describes treatment for young people that is multidisciplinary, pragmatic, flexible and patient-centred. It seems plausible that this approach is contributing to the good outcomes, but there was no control group for comparison.
Overall, this study strikes me as an important one. It is very large, used fairly strict diagnostic criteria, and had a very high follow-up rate (particularly considering the young and mobile age-group studied). The recovery figures were backed up by high functional scores, and the overall good outcomes were supported by the high levels of people working or studying full-time and also managing a social life alongside that.
There is some uncertainty over the actual rate of recovery but it could be as high as two-thirds (68%) - at least for those with a post-infectious onset. Many of the remainder have reasonable levels of functioning, able to work part time. However a minority of around 10% remain severely affected.
We desperately need similar large and well-done studies of long-term outcomes for adults with ME/CFS.
*Check the study paper supplementary materials for details of the questionnaires used.