Exercise combined with Acceptance and Commitment Therapy for chronic pain: One-year follow-up from a randomized controlled trial

BACKGROUND

Acceptance and Commitment Therapy (ACT) is a type of Cognitive Behavioural Therapy, which has demonstrated positive outcomes in individuals with chronic pain. The purpose of this study was to compare the effect of an 8-week programme combining Exercise with Acceptance and Commitment Therapy (ExACT) with a standalone supervised exercise programme at 1-year follow-up.

METHODS

One hundred and seventy-five people with chronic pain were randomly assigned to ExACT or supervised exercise only. The primary outcome was pain interference measured with the Brief Pain Inventory-Interference Scale. Secondary and treatment process outcomes included pain severity, depression, anxiety, pain catastrophizing, pain self-efficacy, fear avoidance, pain acceptance, committed action, healthcare utilization, patient satisfaction, and global impression of change. Estimates of treatment effects at 1-year follow-up were based on intention-to-treat analyses, implemented using a linear mixed-effects model.

RESULTS

Eighty-three participants (47.4%) returned the outcome measures at 1-year follow-up. No significant difference was observed between the groups for the primary outcome, pain interference. There was a statistically significant difference between the groups, in favour of ExACT for pain catastrophizing. Within group improvements that were observed within both groups at earlier timepoints were maintained at 1-year follow-up for many of the secondary and treatment process outcomes. ExACT group participants reported higher levels of satisfaction with treatment and global perceived change.

CONCLUSIONS

The study results showed no significant difference between the two groups for the primary outcome pain interference at 1-year follow-up. Future research could investigate factors that may predict and optimize outcomes from these types of intervention for people living with chronic pain.

SIGNIFICANCE

Few previous randomized controlled trials investigating ACT for chronic pain have included long-term follow-up. This study found that Exercise combined with ACT was not superior to supervised exercise alone for reducing pain interference at 1-year follow-up. Further research is necessary to identify key processes of therapeutic change and to explore how interventions may be modified to enhance clinical outcomes for people with chronic pain.

Simultaneous presence of antiviral activity and its degrader in Bacillus extracts

Extracts of uninfected Bacillus species ATCC 27877 cells contained both an antiviral activity and a degrader for this activity. The antiviral activity was stable to 90 degrees C, caused a rapid inhibition of phage adsorption, and resulted in a gradual loss of phage infectivity. When extracts were incubated at 37 degrees C, the degrader inactivated the antiviral activity and the degrader was retained. When the extracts were heated at 90 degrees C, the degrader was inactivated and the antiviral activity was retained. A comparison was made of these two activities in extracts from cells of various incubation ages. The apparent association of maximal antiviral activity with prespore cells seemed due to the high content of degrader in vegetative and stationary cells. Both antiviral activity and its degrader appeared to be characteristics of vegetative cells.

The influence of cortisone on experimental viral infection. VII. Kinetics of interferon formation and its inhibition with hydrocortisone in relation to viral strain and virulence

A comparative study was undertaken of the pathogenesis of infection of the allantoic sac of the chick embryo with three influenza viruses of differing virulence, and of the influence of hydrocortisone on the course of infection. Judged on the basis of earlier onset and greater degree of inflammatory response and diminished survival time of infected embryos, Mel. and Lee viruses were markedly more virulent than PR8, despite the earlier appearance of virus in PR8-infected embryos. Interferon appeared first and in greater quantity in the allantoic fluid of Lee-infected embryos and latest with PR8 infection. Thus, there was no correlation of avirulence and better interferon production with the viruses under study in the present system. Furthermore, evidence obtained suggested that Lee virus ("virulent") was most susceptible to interferon action, and also that viral synthesis in the chorioallantoic membrane with PR8 ("avirulent") persisted after the appearance of interferon. The injection of hydrocortisone within 2 hr of the initiation of infection delayed the synthesis of all three viruses; had no significant effect upon the inflammatory response; and transiently inhibited the synthesis of interferon, while prolonging the survival of Lee- and Mel.-infected embryos. Late administration of hydrocortisone suppresses both the inflammatory response and the production of interferon. Only in the case of Lee virus infection did hydrocortisone administration lead to augmentation of final yields of virus with the low infection multiplicity employed in the present experiments. It is postulated that Lee virus is a better inducer of interferon because its infectivity in vivo is more rapidly inactivated. As a consequence synthesis of Lee virus is more under the control of endogenous interferon than is the case with PR8 or Mel. virus. Therefore, inhibition of interferon synthesis with hydrocortisone has a greater influence on final yields of Lee virus.

The influence of cortisone on experimental viral infection. VI. Inhibition by hydrocortisone of interferon synthesis in the chick embryo

The initial observations that cortisone may act as an inhibitor of viral interference (11, 4) are now explicable as an inhibitory effect on interferon synthesis. The suggestion that the action of interferon is also inhibited by cortisone or its analogues (6) has not been confirmed in a plaque reduction type of interferon assay system in which autointerference by the challenge inoculum is a lesser problem. In this respect, the present results are in accord with those obtained by DeMaeyer and DeMaeyer (8) with hydrocortisone in a system in which a low multiplicity (0.1) Sindbis virus infection in monolayer culture was employed with cytopathic effect (CPE) as an end-point. It has been shown that hydrocortisone is restrictive to the synthesis of interferon induced by inoculation of either infective or inactivated virus into the chick embryo, and that this inhibitory effect is temporary. However, in another study in the chick embryo, three spaced injections of hydrocortisone (0.25 mg/dose) prevented the appearance of detectable interferon during the entire 64 hr observation period following inoculation of 10(3.3) EID(50) of Lee virus (12). The importance of explicit definition of experimental conditions in assessing hormonal effects on infection is illustrated by the capacity of hydrocortisone either to inhibit or increase interferon synthesis in vitro, depending on the proportion of inactivated and infective virus in the inoculum employed, and the time at which interferon is measured. As suggested previously, it is not unlikely that similar shifts in hormone-virus-interferon balance may operate in vivo to influence the outcome of infection.