NICE guidance (2005) recommends that OCD is treated using a stepped care approach. A key part of the stepped care model is the provision of Low Intensity (LI) interventions, based on Cognitive Behavioural Therapy (CBT) and including Exposure and Response Prevention (ERP) principles.

Currently the evidence for Low Intensity interventions for OCD is unclear, as most of the research included in the 2005 NICE guidance on low intensity treatment for OCD was in fact attenuated CBT delivered by CBT therapists over a few sessions, rather than by Psychological Wellbeing Practitioners (PWPs). Previous trials have indicated that supported self-help may be an effective treatment for OCD (Lovell et al., 2005).

The aim of the OCTET (Obsessive Compulsive Treatment Efficacy Trial) was to:

• Assess if guided self-help (GSH) or Computerised Cognitive Behavioural Therapy (cCBT) provided rapid improvement in OCD symptoms at 3 months compared to waiting list for therapist-led CBT
• To assess if GSH or cCBT prior to therapist-led CBT provided longer term improvement in OCD symptoms at 12 months compared to therapist-led CBT alone
• To consider if accessing GSH or cCBT reduces uptake of therapist-led CBT over 12 months
• To assess if access to GSH or cCBT improved satisfaction at 3 months compared to waiting list
• The trial also included an economic and process evaluation.

Methods

The study was a pragmatic three-arm multicentre randomised controlled trial (RCT) of 473 eligible patients recruited from IAPT, primary and secondary care settings in 15 NHS Trusts in England.

Participants were included for the study if they were:

• 18 years old and above
• On a waiting list for High Intensity (HI) CBT
• Met the DSM-IV criteria for OCD (assessed using the MINI interview)
• Scored 16+ on the Yale Brown Obsessive Compulsive Scale Self-Report (YBOC-SR)
• Reported the ability to read English at a level of 11 years and above.

Participants were excluded if they:

• Were actively suicidal
• Had organic brain disease
• Had a current psychosis
• Had a diagnosis of alcohol or substance disorder
• Were receiving psychological treatment for OCD
• Had language difficulties that would preclude participation.

The trial interventions were:

1. cCBT (Computerised Cognitive Behavioural Therapy)
2. GSH (Guided Self-Help)
3. The comparator was waiting-list for therapist led CBT (the time of waiting list varied between services and there was no mandated minimum waiting period).

cCBT was delivered using the commercially available OCFighter program (cbtc.co.uk), which contains 9 steps. Participants were advised to use the programme at least six times over a 12-week period and received six 10-minute support telephone calls which focus on risk assessment, progress review and problem-solving.

GSH was delivered using the ‘Overcoming OCD: a workbook’ (Lovell & Gega, 2011), which focused on Exposure and Response Prevention (ERP) principles. Participants in this condition received weekly guidance, with an initial 60-minute session and 10 half hour follow up session over 12-weeks. The focus of support sessions was to explain the workbook, help devise goals, risk assessment, support homework, progress review and problem solving.

Both interventions were delivered by 93 psychological well-being practitioners (PWPs). These are often graduates with no prior clinical qualifications and receive 12 months training that follows a national curriculum (REF) and is a mix of formal teaching and clinical practice to deliver low intensity interventions for depression and anxiety. As OCD training is outside of the remit of the national training program, the PWPs in this trial received additional training over three days in both interventions by the research team.

Fidelity to treatment was evaluated by raters who were blind to outcomes.

The primary outcome measure was the YBOC-SR and secondary outcomes included in the trial were CORE-OM, PHQ-9, GAD-7, WSAS, the IAPT employment questionnaire and the CSQ-8.

Outcomes were collected at baseline, 3 month, 6 month and 12-month follow up after randomisation.

Results

• In the cCBT (Computerised Cognitive Behavioural Therapy) condition:
  • 59% of participants received at least one session with a PWP
  • The mean number of sessions was 2.3 (SD 2.5)
  • The average length of session was 13.4 minutes
  • The mean number of steps completed was 3.7 (SD 3.2)
• In the GSH (Guided Self-Help) condition
  • 66% of participants received at least one session of GSH
  • The mean number of sessions: 4.1 (SD 4.3)
  • The mean session length for session one was 57 minutes and 31 minutes for sessions 2-11
• Fidelity assessment were low with recordings being provided for 26% of GSH sessions and 17% of cCBT sessions. Of the recorded sessions, the majority were rated as good or excellent
• In relation to the study aims and the benefits of these interventions:
  • There was no statistically significant benefit of access to cCBT (adjusted mean difference -0.71, 95% CI -2.12 to 0.70, p=0.325)
  • There was a statistically significant benefit of GSH, but this did not meet the pre-specified clinically important difference of 3 points (adjusted mean difference -1.91, 95% CI -3.17 to 0.70, p=0.325)
• Analysis of satisfaction data indicated:
  • No differences in satisfaction between those receiving cCBT compared to waitlist (adjusted mean difference -0.31, 95% CI -2.07 to 1.45, p=0.732).
  • There was a trend that participants in the GSH condition were more satisfied than those allocated to the waitlist condition, but this was not statistically significant (adjusted mean difference 1.69, 95% CI -0.04 to 3.42, p=0.055)
  • Patients receiving cCBT were less satisfied than those receiving GSH (adjusted mean difference -2.00, 95% CI -3.63 to -0.37, p=0.016)
• There was no significant long-term benefit from accessing either cCBT or GSH at 12 months.
• Post-hoc analysis indicated that cCBT and GSH were non-inferior to waitlist at 12 months.
• Both cCBT and GSH led to a reduced uptake in therapist-led CBT
  • cCBT (adjusted OR 0.34, 95% CI 0.15 to 0.79, p=0.011)
  • GSH (adjusted OR 0.27, 95% CI 0.12 to 0.60, p=0.001).

Conclusions

The authors concluded that low intensity GSH and cCBT for OCD did not provide more rapid symptom relief prior to therapist-led CBT or demonstrate significant benefit at 3 or 12 month follow up.

The authors also concluded that access to low intensity interventions prior to a therapist-led CBT led to significant reductions in the uptake of CBT treatment. However, those that did access treatment did not show any deterioration in outcomes at 12 months.

The trial results indicate that currently there is no support for the role of low-intensity interventions for OCD.

Strengths and limitations

This is the one of the largest trials of psychological interventions for OCD ever conducted. The study adhered to CONSORT reporting guidelines and the trial protocol was pre-registered as were the planned analysis, so there is a high level of transparency of reporting. The trial was also conducted in a routine clinical setting and used a commercially available cCBT program, which gives this research a level of external validity.

However, there were several limitations identified by the authors in this pragmatic trial:

Firstly, there were a high number of PWP therapists in trial, which may have limited the ability to deliver the trial treatments at an acceptable level of competence and skill, as OCD treatment is not part of the core PWP training Curriculum and this may indicate that PWPs require further training in how to implement ERP based interventions effectively, as the trial training may not have met this need for the PWP population.

Additionally, the fidelity checks in the study were limited so it is not clear if the participants received the treatment as identified in either the trial conditions or the therapist-led condition. It was not possible to control the duration of the waiting list and there was an indication that the relatively rapid access to therapist-led CBT reduced any effect of the trial interventions. Also, medication could not be controlled for so the effect on overall outcomes cannot be determined. The authors also identified that the participants in this study experienced more severe symptoms of OCD than other studies that evaluated low intensity (LI) interventions and it was hypothesised that might be a potential explanation for the variation in effect between this trial and previously conducted trials.

More concerning is the low levels of treatment adherence across the trial groups. The mean number of completed sessions in both interventions was low (2.9 and 4.6 for cCBT and GSH, respectively) which was substantially lower than the planned treatment (9 steps for cCBT and 11 sessions for GSH). In effect the planned treatment was not delivered to most participants so the real effect of a full dosage of either treatment is unknown. Additionally, the planned GSH treatment appeared substantiality different to the current commissioned model of care that primary care services deliver (e.g. 4-6 sessions of LI treatment) and there are questions about the scalability of the GSH treatment in its current form. There also appears to be a negative effect of LI treatment on therapist-led treatment, which raises questions over appropriate targeting of treatment to ensure that those who would benefit from psychological intervention are not lost to attrition because of a multistage pathway. The potential harms of this observation should be explored in future research. It may be that LI interventions risk of being used as a staging area to manage therapist-led CBT, rather than being led by clinical need.

Overall the OCTET trial raises more questions than it answers regarding the role of low intensity interventions for OCD. Currently there is no indication that guided self-help or computerised CBT for OCD are clinically effective.

Links

Primary paper

Lovell K, Bower P, Gellatly J, Byford S, Bee P, McMillan D, et al. (2017) Low-intensity cognitive-behaviour therapy interventions for obsessive-compulsive disorder compared to waiting list for therapist-led cognitive-behaviour therapy: 3-arm randomised controlled trial of clinical effectiveness. PLoS Med 14(6): e1002337.

Other references

National Institute for Health and Clinical Excellence (2005) Obsessive-compulsive disorder: care interventions in the treatment of obsessive-compulsive disorder and body dysmorphic disorder. London: NICE.

Lovell K, Ekers D, Fulford J, Baguley C, Bradshaw T. (2005) A pilot study of self-help manual with minimal therapist contact in the treatment of obsessive-compulsive disorder. Clinical Effectiveness in Nursing, 8(2):122-127.

Increasing Access to Psychological Therapy (2015) National Curriculum for the Education of Psychological Wellbeing Practitioners (Third edition, updated and revised, March 2015).