The introduction points out that "recovery from an illness is a fundamental concept in health care, but its operational meaning remains vague". It describes the difference between the definitions of 'recovery' and 'improvement' but also mentions that these terms are commonly conflated in the literature, and that there is no consensus for how recovery from CFS is defined, which may be in part due to the "absence of biomarkers or diagnostic tests". It is also pointed out that these problems are not unique to CFS and are common in some other chronic physical and mental conditions.
22 studies made the inclusion criteria and are presented in Table 1. The 'operational' definitions of recovery are very varied. The paper refers to the strictest definition of recovery in the Knoop et al. (2007) paper as "the most stringent standard found, although it was rarely used". This contradicts White et al's claim that the definition of recovery used in the PACE trial was more conservative than that of Knoop et al (which was already clearly wrong when examining both papers).
In a 5-year follow-up study of a randomized control trial of cognitive behavioral therapy in CFS [19], complete recovery was defined by these changes in fatigue and function: no longer meeting Oxford (UK) criteria for CFS, being employed full time, and scoring within the normal range on fatigue and function self-report questionnaires. Using this multi-domain definition of recovery, the authors reported a 23 % recovery rate [19].
A similar definition of recovery was used by White et al. [20] in their recent report on recovery from CFS following a large randomized trial [21] of CBT, graded exercise therapy (GET), adaptive pacing therapy (APT), or specialist medical care (SMC). Patient recovery was defined as being within the normal range on self-report measures of fatigue and physical function, no longer meeting Oxford criteria for CFS, and reporting an overall clinical global rating of ‘‘very much better’’ or ‘‘much better.’’ Patient recovery rates ranged from 7 to 22 %, depending on treatment condition. A ‘‘clinical’’ recovery definition was also provided, which indicated that a patient no longer met Fukuda et al. [22] criteria for CFS, or London criteria for myalgic encephalomyelitis (ME) [21], an approximate equivalent of CFS. Application of these clinical criteria yielded similar recovery proportions [20].
The above was somewhat annoying because it can give the misleading impression that the thresholds used in both studies were similar and therefore the PACE trial 'recovery' rates were comparable.
This part was good:
"the current absence of definitive tests for CFS may indicate the need for recovery criteria that set high but reasonable standards for behavioral recovery that approach restoration of pre-morbid health". The physical function threshold used in the PACE trial for 'recovery' was insulting. I wish this paper went into how it overlapped with entry criteria, and that most of the so-called 'recovery' criteria were apparently changed after the outcome data were in.
As the authors of this paper indicate, there are important elements of recovery to capture, such as pre-morbid activity levels, reduction in major symptoms (too much focus on fatigue overestimates recovery rates), return to normal healthy function, employment, and perceptions about health i.e. feeling recovered.
This part was generally good:
Recovery versus successful adaptation
Recovery versus successful adaptation In examining its various definitions, many ‘‘recovered’’ patients may not be reaching full recovery levels that indicate a return to health (assuming some adjustment for aging). Given that the majority of studies relied on patient self-report and did not utilize more objective measures of recovery, such as return to work or school [44] (e.g., following a medical leave), or laboratory-based assessments (e.g., 6-min walk test), it is difficult to know whether substantial recovery occurred. These arguable points have been expressed in letters to the editor that dispute recovery labeled outcomes in published behavioral intervention studies in CFS, e.g., [13, 20, 45, 46].
In the absence of definitive measures, a more modest interpretation of ‘‘recovery’’ might characterize such outcomes as successful adaptation of illness-related behavior and attitudes to ongoing but perhaps diminished illness [47]. For instance, patients deemed ‘‘recovered’’ following treatment may have achieved their success by doing much less activity, i.e., symptom-producing behaviors, than they were doing prior to the intervention [48]. In this scenario, assessed functional abilities and fatigue may well improve perhaps within a normative range, but not to a level that reflects the patient’s pre-morbid abilities. Relevant to this point, Whiting et al. [44] in her review of intervention studies in CFS presented the logical possibility that patients’ perceptions of improvement after intervention could be due to lowered expectations of their abilities, rather than heightened functioning.
Empirical support for this more modest interpretation of recovery may be found in behavioral treatment studies which incorporated the relatively objective behavioral measure of actigraphy [49]. Although the cognitive behavioral model of CFS predicts increased physical functioning as a result of the intervention, these otherwise successful trials [50] did not find significant changes in actigraphy-measured physical activity from pre- to posttreatment or between intervention and control groups. One interpretation of the absence of objective activity change is that improved or recovered patients may have continued to avoid activity levels that provoked debilitating postexertional symptom flare-ups [i.e., post-exertional malaise (PEM)], considered a core symptom of the illness according to a recent case definition [41]. Perhaps these ‘‘recovered’’ individuals are living within a safety ‘‘envelope’’ that avoids PEM [51], rather than enjoying resilient levels of recovered function and symptom alleviation. This type of outcome would seem to be more consistent with a hypothesis of successful adaptation rather than recovery.
However, the above goodness is balanced out with the next section titled "Recovery and pre-morbid functioning" which contains questionable speculation about action-proneness and 'illness-producing activity levels'. Yes, there are 'healthy limits', and perhaps over-exertion when healthy is a problem that applies to the occasional patient, but it annoys me how some researchers have used this concept to justify questionably low thresholds for normal function (or to explain away the failures of their own treatment models) as if that should be acceptable to most patients who have completely recovered.
This next issue is important to, but as others already commented on, part of it waters down the meaning of genuine complete recovery with a questionable application of pragmatism.
Patient perceptions of recovery
Finally, patients’ perceptions of their recovery is a particularly important issue that was not assessed in the majority of reviewed papers. For instance, individuals who meet criteria for an operational definition of recovery may not view themselves as recovered. This divergence may be due to the patient’s desire to fully restore health and well-being as indicated by an absence of symptoms, elimination of all functional impairments, and the reduction in psychological distress [56]. This level of expectation comports with common views of recovery and may constitute an important element of assessment. Perhaps the most sustainable levels of recovery evolve from a more flexible or adaptable view of potential illness vulnerability that is informed by the patient’s lifestyle and its relation to illness flare-ups. As suggested by Ene [57], ‘‘the quest for treatment is not only a quest for relief of symptoms; it is also seen as a journey to find personal balance in one’s life. Patients approach the recovery process by making decisions as to what works for the individual, rather than pursuing each recommended biomedical treatment.’’ Inquiring about how patients’ view recovery with respect to their own lives could reveal a full range of realistic and unrealistic expectations that may inform treatment, patient education, and the design of outcome studies.
As Esther said, which deserves repeating:
"If they are going to expect patients with CFS to put up with some rubbish version of 'recovery' because we were previously so very over-active, they'd better have some good evidence that this was actually the case. Anyway - it would still be fair to expect 'recovered' CFS patients to be able to do as much as healthy controls. [...] "I'm not on a 'quest' for treatment, and have no interest in medical staff playing any role in finding a 'personal balance' in my life. Also - it's a bit rich to talk about patients having 'unrealistic expectations' when those expectations will have been shaped by the 'rousing reassurance' or medical staff, or 'encouraging' claims about recovery that come from misleading and manipulated criteria."
Conclusions and recommendations
This systematic review found a broad range of recovery criteria in CFS outcome studies that utilized a multitude of measures to evaluate different domains. All 22 reviewed articles defined recovery uniquely, based on an array of illness characteristics and measures. Reported recovery rates ranged from 0 to 66 %. To increase comparability, the use of a consistent definition across studies is recommended. In keeping with commonly understood conceptions of recovery from illness, we suggest broadly based assessments in CFS studies that include criteria for normalization of symptoms and functioning as well as patient perceptions that indicate a return to health. In addition, another important aspect of the recovery concept, that is, recovery time following physical and mental exertion requires further investigation as the control of this process may be related to illness improvement and potential recovery. Finally, in the absence of a thorough evaluation for recovery, other more precise and accurate labels (e.g., clinically significant improvement) may be more appropriate and informative.
Overall the paper is OK and highlights important issues. It contains soft criticism of how the term 'recovery' has been inappropriately bandied around and conflated with 'improvement', but as A.B. stated, does not go far enough. I also wish they discussed the implications of false hope and harmful expectations from patients that comes from inadequate definitions of recovery being misleadingly presented as what healthy people would regard as healthy.
I understand there are practical difficulties in defining it, but recovery from CFS should not be seen as some ambiguous mystery and should not be watered down by concepts which sound like apologizing for the remaining symptoms of CFS. There needs to be a more consistent and universally accepted definition of recovery. Patients should be consulted more on how recovery should be defined. The current mess is disheartening.