In this randomized controlled trial we have shown that a 20-week group treatment with two new treatments; TY and MCBT, or CBT (control), improved HRQoL in severely sick patients on sick leave because of burnout, which supports our hypothesis. The patients were sicker than most patients in earlier studies and they had in most cases been sick for a longer time at inclusion, than patients in previous studies. The treatments had a good effect in general on HRQoL as measured by SWED-QUAL and the effects were larger than we had expected. Effect sizes were medium or large in all the significant subscales in all three groups, except for one in CBT. Comparison between the treatments showed a slightly larger effect sizes for TY and MBCT, in comparison to CBT, in several of the subscales.

Emotional wellbeing

The large impact on emotional well-being, one of the main components in burnout, was seen in all three subscales, “positive affect,” “negative affect” and “role limitation due to emotional health”(Tables 4 and 6). The improvement in TY may be caused by the mild physical movements, the rhythmic, regular breathing and the constant awareness training during the exercises [33, 55, 56]. These are known to have an effect on both the parasympathetic and the sympathetic nervous systems, as well as on positive and negative affect (emotions) [57, 58]. Also, the results in the TY group might have benefitted from employing exercises in the physical, emotional and cognitive domains simultaneously. The MBCT treatment targets mostly the cognitive and emotional part of the individuals’ experience (Segal et al., 2002).. It is found that patients who suffer from stress, anxiety and depression often use the strategy of ‘experiential avoidance’. This strategy is the alteration of frequency of thoughts, feelings, bodily sensations, or memories. Although these alterations may not bring any real comfort or lessen the severity of suffering, those practices end up being even more costly, ineffective and damaging to the patients habitually using it. One of the ways to encourage patients to replace experiential avoidance is with mindfulness acceptance. This is to accept real experiences, emotions and thoughts as they are. It is an intentional behavior that alters the function of inner experiences from events to be avoided, to a focus on interest, curiosity, and observation as part of living a valued life. MBCT has previously show good effect on burnout in a group of primary care physicians [59] and mindfulness has shown to be effective in primary care patients suffering from stress related disorders [60]. In CBT treatment the improvement might be due to cognitive changes caused by the use of different kinds of methods to detect negative thoughts and to replace them with more positive ones. This may in turn have an effect on “positive” and “negative affect.” Previous studies have shown that CBT has a good effect on positive and negative affect [61].

Cognitive function

Emotion is also known to be closely connected to cognitive function [62, 63], and may affect emotional wellbeing, and vice versa. Cognitive function, which signifies concentration ability, understanding capacity, memory and the capacity to focus on day-to-day life, is an important component of burnout. The improvement in scores in “cognitive function” is similar, although TY treatment uses different methods of cognitive training, from MBCT and CBT. This indicates that TY might be helpful for people who, for various reasons, find it difficult to participate in CBT or MBCT. Cognitive function has previously been shown to increase after six weeks of Yoga training in breast cancer patients [64], and in menopausal women after a Yoga program [65]. Also, in a group of elderly participants cognitive function increased together with emotional wellbeing after following a mindfulness program [66]. Numerous studies have shown a good effect on different aspects of cognition [73, 76], which supports our findings.

Physical wellbeing

The subscale score at baseline for “physical functioning” was comparatively high in all three groups; probably due to their relatively young age and that they were previously healthy. The results are in accordance with earlier findings in a group of persons experiencing emotional ill-being and attending a mind-body-medicine course [67]. Furthermore, previous findings have shown that emotional and cognitive functions are much more readily affected than physical function in a stressful situation [68].

The subscales concerning physical wellbeing showed inconsistent patterns in the three groups with betterment in some subscales but not in others, despite the increase in emotional wellbeing. Burnout patients are generally inclined to negative affect and consistently report declining health symptoms, such as mental health and somatic complaints [69] Furthermore, negative affect has a weak and inconsistent association to objectivity in regards to assessed health status [70]. Suner-Soler et al. (2013) finds that high levels of burnout especially in the “emotional exhaustion” component, leads to deterioration in the health-related quality of life both physically and mentally [71]. And recent evidence suggests that burnout also has a negative impact on physical health [72]. Thus, we expected that along with the improvement in emotional wellbeing there should be a simultaneous improvement in physical wellbeing. In TY treatment, bodywork in the form of mild yoga postures and movements might give the participants a more accurate idea about their level of functioning. Here, in TY, the subscale “physical functioning” was non-significant while “role limitation due to physical health” showed a significant increase. A possible explanation might be that while “physical functioning” also contains questions on heavy work and strenuous exercises, the subscale “role limitation due to physical health” concerns day-to-day activities that a person usually performs anyway and an improvement here may probably be experienced earlier. In a previous study examining the effects of mild yoga it was found that 83% of the yoga practitioners improved in overall physical function and capacity [73], but these patients were older and at risk for cardiovascular disease. The MBCT group showed the opposite pattern, with a significant increase in the subscale “physical functioning” but a non-significant increase in the subscale “role limitation due to physical health”. This difference we assume exist because of the already higher, baseline median score, and therefore the subscale “role limitation due to physical health” do not show a significant increase. The significant increase of “physical functioning” could be counted as a positive sign for the burnout patients. In the CBT treatment group the median subscale score for “physical functioning” was high at baseline, but despite the increase in “role limitation due to physical health,” emotional well-being, cognition and sleep the subscale score for “physical functioning” actually did not change. CBT treatment comprised relaxation as a means of increasing body awareness in addition to the cognitive exercises and strategies, but this was apparently not enough to counteract the influence of burnout over time. Also, the scores were high from the beginning, which might have made further improvement in the scores less likely. These findings contradict previous research showing that CBT improved physical function in patients on sick leave for stress-related disorders as measured by SF-36, a HRQoL questionnaire similar to SWED-QUAL. However, in that study the participants’ baseline scores were not reported [74]. The low, non-significant improvement of the subscale “pain”, in all three groups was a surprise. Also, there was only a low effect size in TY and no effect size at all in CBT, while MBCT had a medium effect size. Pain is often one of the first symptoms experienced in stress related disorders, and we expected somehow that there should be an improvement after treatment. But, as pain is an unspecific symptom, it might be the other way around; pain may be the last symptom that disappears. Here, MBCT had a significant increase in “physical functioning” which might have influenced the improvement in the subscale “pain”, while in TY the low increase might be caused by the bodywork which made them more in contact with their body. This might have made them experience, and assess their pain to a larger extent.

Sleep

The subscale sleep showed good results in the all three groups group. In TY this impact on sleep may be explained by a combination of the relaxing and overall stress-reducing effect together with increased calmness, lowered negative affect and improved body awareness, which TY is reported to have [75]. In previous studies yoga has also been shown to have a good effect on sleep disturbances [73], which is in line with our results. The subscale “sleep” was the one most improved for the MBCT group, and that improvement would have helped reduce the severity of burnout, as previous studies showed that insufficient sleep predicts burnout [76]. An eight week treatment containing mindfulness meditation has previously shown an effect on chronic Insomnia in a group of adults [77], and MBCT improved polysomnographic and subjective sleep profiles in antidepressant users with sleep complaints [78], which support our findings. In CBT, which is a common therapy used for sleeping problems, showed good effect on insomnia in a group of depressed patients ([79, 80].

The differences between the groups regarding the subscales “satisfaction”.

The improvement in sexual function seen in the TY group was probably because of the increase in both emotional and physical well-being. The result is in accordance with studies by Dhikav et al. [81, 82]. In MBCT the non-significant improvements in “satisfaction with partner functioning” and “satisfaction with family functioning” contrasted to “sexual functioning” which had a significant effect in MBCT. This result evoke an interesting question, how can sexual functioning score significantly higher for MBCT when satisfaction with family functioning and partner functioning scored low? Wändell et al. found psychiatric conditions would have been the second most important predictor, next to age of sexual dysfunction in diabetic patients [53]. Fernros et al., also found that physical functioning had a strong correlation with sexual functioning [67]. In this study, physical functioning, emotional health and cognitive functioning are all significantly high for participants in MBCT, and thereby concluding that, a low score in partner and family functioning may not necessarily affect sexual functioning.

The trend for TY and to some extent the trend for MBCT over CBT in the subscale “negative affect” might indicate that these two treatments have an additional effect compared to CBT. This is in line with our quest but more studies are needed to explore this.

Although a general increase in HRQoL is not necessarily followed by an increase in work ability, an improvement in the scores of subscales “role limitation due to emotional health” and “role limitation due to physical health” may indicate an increased capacity to work. These two subscales deal with how our role functions in various professions are affected by how one feels emotionally and physically. All three treatment groups, TY, MCBT and CBT had large improvements in these subscales. Previous research has not been able to show an increased work ability with CBT as a stand-alone treatment, but usually these treatments are shorter (8–16 weeks) [28].

When the scores in the TY, MBCT and CBT treatment were compared with those of a healthy group working full time [18], all three groups showed decreased median differences in scores after treatment compared to the healthy group. In ten subscales in the TY group, in seven subscales in the MBCT group and in five subscales in the CBT group, the difference in subscale score between the treatment groups and the healthy group were no longer significant after median regression (data not shown), which indicates a good effect of the treatment.

As the data are ordinal, group-wise and between-group analyses of scores were done using nonparametric methods. For the sake of comparison with previous studies, percent increase and Cohen’s D were calculated. An analysis with parametric methods was also carried out, and it yielded the same results concerning P-values. The results pre- and post treatment differ slightly when presented as means instead of medians, but the general picture remains. Another phenomenon, “regression towards the mean,” might have influenced the scores. For example, if SWED-QUAL is filled in a second time in close approximation to the first occasion, the scores tend to be closer to the mean. This might have influenced the scores to some extent in our group, but it is unlikely to have changed the results.

Strengths and limitations

One of the strengths of this study is that it is a RCT, and that the study group was a clinical sample of patients with different occupations, reflecting the situation of these patients on sick leave in occupational medicine and in primary care. Also, they were diagnosed with Exhaustion Syndrome beside self-assessment. Furthermore, HRQoL was measured by SWED-QUAL, which comprises questions covering most components known to be affected in burnout. Also, SWED-QUAL has been shown to be stable over time, so that a change in scores reflects a real change [45]. The interventions were group treatments, which may facilitate implementation in the health care system and as prevention at work sites and companies. The limitations were the small group size and that there were few men, although it reflects the actual situation. All the patients had actively applied to participate in the study, which reflects initiative and a certain level of strength, and thus patients with less motivation and strength are not represented. Also, all participants were receiving sickness benefits, and therefore persons outside the labor market were not included in the study. In addition, many of the participants increased their level of activity during the study. This in turn resulted in reported increased symptoms and less self-reported improvement, which may have negatively influenced the SWED-QUAL subscale scores and thus underestimating the effects of the treatment. The therapies in the study were provided by the first and second authors, which may have influenced results. Another limitation is that the restricted sample size did not allow sub analyses based on factors such as gender, age, different professions or level of sick leave. Although some individuals reported that the stressor inducing the symptoms leading to exhaustion syndrome was their personal situation, we do not know if the situation at work also contributed to the symptoms developing, as we did not ask for this information specifically. Despite the improvement in HRQoL, we do not actually know whether the participants’ levels of burnout decreased or not. In summary, this study did not have the basic foundation to judge whether TY, MBCT and CBT treatments certainly decreased the suffering of the burnout patients. Nevertheless, it showed that TY, MBCT and CBT as group treatments positively influenced several subscales of SWED-QUAL for patients with burnout who were on sick leave.

Implications for health care and research

We assume that the results are generalizable to patients undergoing rehabilitation in occupational medicine and primary care settings, where most of these patients are found, despite the limitations of inclusion and exclusion criteria such as age, gender, whether working or not, under- or overweight and having other diseases. Also, we believe that the results are generalizable to burnout patients on sick leave in other health care settings such as psychiatric, internal or emergency medicine, as patients initially might seek care outside of occupational medicine and primary care due to the wide variety of symptoms. More therapies, with different working components, could help patients improve their HRQoL and decrease the risk of future morbidity, both as early intervention and in severe cases, as in this study. All three group treatments can be used as health promotion and burnout prevention in occupational health care management in companies and, after the active treatment phase is over, to prevent relapse. This is an advantage, as these can help patients handle stress at work and in their day-to-day lives.

Future research with larger groups, effective sample size determination, and with equal representation of both genders is needed to confirm the results from this study and to further explore the efficacious components in each of the treatments. Also, studies to explore whether increased HRQoL decreases burnout and improves return-to-work rates after longer treatment with TY, MCBT and CBT would be beneficial, as well as studies which combine TY, MCBT and CBT with workplace intervention methods. A follow-up study is planned to evaluate the long-term effects together with the relapse ratio and cost-effectiveness calculations.