Factors predicting the transition from acute to persistent pain in people with ‘sciatica’-the FORECAST longitudinal prognostic factor cohort

ISRCTN ISRCTN18170726
DOI https://doi.org/10.1186/ISRCTN18170726
Submission date
30/01/2023
Registration date
10/02/2023
Last edited
01/10/2024
Recruitment status
No longer recruiting
Overall study status
Ongoing
Condition category
Musculoskeletal Diseases
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
Sciatica is very common and is caused by injured or irritated nerves in the lower back. Sciatica causes pain, tingling or weakness in the leg. It can have a devastating effect on everyday life. For instance, patients cannot complete their normal work or care for their families. Sadly, about one in three patients develops persistent sciatica pain. We currently do not understand why some patients develop persistent pain and why some recover. Previous research has demonstrated that usual clinical findings (e.g., depression or routine MRI) cannot predict persistent sciatica. A different approach is therefore needed to identify who may develop persistent sciatica. This is the goal of the FORECAST study.

FORECAST is performed by a team of medical doctors, neuroscientists, statisticians, and MRI specialists at Oxford University. The team also includes patient partners who help us design and run our study. Our FORECAST study is different to previous studies. Whereas previous studies only included a short clinical examination, we will perform a detailed set of tests. We hope that the detailed tests can predict who develops persistent pain. The questions we hope to answer in the FORECAST study comprise whether the detailed tests identify different subgroups of patients with sciatica and which of these detailed tests predict pain persistence. The FORECAST study is a substudy of the PiPL platform. PiPL aims to understand prognostic factors for pain persistence and the nature of nerve-related pain in patients with different peripheral nerve injuries and includes many different substudies in different patient populations.

Who can participate?
Adults with recent onset of sciatica (symptoms<3 months)

What does the study involve?
The FORECAST study is a substudy of the PiPL study (IRAS 241777). In the first assessment, the team will perform detailed tests. This includes detailed sensory nerve testing (quantitative sensory testing) and a precise set of questionnaires to evaluate the type of pain and emotional well-being. A blood sample will also be taken to look for signs of inflammation. Some patients will receive specialised magnetic resonance imaging to evaluate the microscopic structure of the small nerves in the back. These images are much more detailed and specialised than routine MRI scans. Patients will be contacted again three months and one year later, to ask whether they still have sciatica symptoms. Statistics will be used to identify patient subgroups and to find out which tests predict pain persistence.

What are the possible benefits and risks of participating?
There is no direct benefit to participants, but the information we get might help improve the treatment of people with sciatica in the future.
There are no particular risks to this study. MRI is considered a safe procedure, and we will only invite people with no contraindications to MRI for scanning.

The results of the FORECAST study will help us better understand the complexity of sciatica and who develops persistent pain. The findings will also help future research. For instance, future studies can examine whether giving more specific treatment to patients who are likely to develop persistent pain can reduce chronic pain. It is hoped that the results of the FORECAST study will help reduce suffering and improve the quality of life for patients with sciatica.

Where is the study run from?
University of Oxford (UK)

When is the study starting and how long is it expected to run for?
The PiPL platform study commenced in January 2018 and the FORECAST substudy runs from May 2021 to September 2025

Who is funding the study?
1. UK Research and Innovation (UK)
2. Versus Arthritis (UK)
3. National Institute for Health and Care Research (NIHR) (UK)

Who is the main contact?
Prof Annina Schmid, annina.schmid@ndcn.ox.ac.uk (UK)

Study website

Contact information

Prof Annina Schmid
Principal Investigator

Nuffield Department of Clinical Neurosciences
John Radcliffe Hospital
West Wing Level 6
Oxford
OX3 9DU
United Kingdom

ORCiD logoORCID ID 0000-0001-7759-0211
Phone +44 (0)1865 223254
Email annina.schmid@ndcn.ox.ac.uk
Prof Annina Schmid
Scientific

Nuffield Department of Clinical Neurosciences
John Radcliffe Hospital
West Wing Level 6
Oxford
OX3 9DU
United Kingdom

Phone +44 (0)1865 223254
Email annina.schmid@ndcn.ox.ac.uk
Prof Annina Schmid
Public

Nuffield Department of Clinical Neurosciences
John Radcliffe Hospital
West Wing Level 6
Oxford
OX3 9DU
United Kingdom

Phone +44 (0)1865 223254
Email annina.schmid@ndcn.ox.ac.uk

Study information

Study designSingle-centre prospective longitudinal prognostic factor cohort study
Primary study designObservational
Secondary study designLongitudinal study
Study setting(s)University/medical school/dental school
Study typeOther
Participant information sheet Not available in web format, please use the contact details to request a participant information sheet
Scientific titleFactORs prEdiCting the trAnsition from acute to persistent pain in people with ‘SciaTica’-the FORECAST longitudinal prognostic factor cohort, a substudy of the PiPL platform
Study acronymFORECAST
Study objectivesThe FORECAST study is a substudy of the PiPL platform study (IRAS 241777).

The aims of the FORECAST study are:
1. To explore mechanism-based subgroups in patients with acute/subacute sciatica
2. To investigate whether a mechanism-based approach can identify factors that predict pain persistence in people with sciatica
Ethics approval(s)Approved 31/05/2018, South Central - Oxford C Research Ethics Committee (Level 3, Block B, Whitefriars Building, Lewis Mead, Bristol, BS12NT, UK; +44 (0)207 1048289; oxfordc.rec@hra.nhs.uk), ref: 18/SC/0263
Health condition(s) or problem(s) studiedAcute/subacute sciatica/low back pain
InterventionThe FORECAST study is a prospective longitudinal prognostic factor cohort study involving patients with acute/subacute ‘sciatica’ and healthy age- and gender-matched participants without symptoms of sciatica/low back pain. The study is based on feasibility data and closely informed by patient and public involvement and engagement (PPIE) activities including feedback from our named patient partners, a six-member patient advisory group, and survey results from participants of the feasibility study. The study will be performed and reported according to the guidelines for observational studies (STROBE) and the statement for transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD).

The study will include patients with acute/subacute ‘sciatica’ and healthy age- and gender-matched participants without symptoms of sciatica/low back pain. Healthy participants are essential to establish normative values for blood markers, somatosensory profiling and neuroimaging.

After a preliminary eligibility screen on the telephone, patients will attend a baseline appointment with a clinically trained investigator (e.g, physiotherapist) at the local University Department. During the baseline appointment, the diagnosis of sciatica will be confirmed, and the prognostic variables will be assessed through a detailed set of clinical phenotyping as described below. Some patients will also undergo an MRI scan of their lumbar spine. We will then follow up with patients over 1 year with monthly pain diaries and the outcomes will be measured at 3 (short-term) and 12 months (long-term).
Intervention typeOther
Primary outcome measurePain persistence measured using the below at 3 months and 12 months:
1. The Sciatica Bothersomeness Index20 (SBI)
2. A Numerical Rating Scale (NRS)
Secondary outcome measures1. Level of disability in activities of daily living measured using the Oswestry Disability Index at 3 and 12 months
2. Self-perceived change measured using a Global rating of change (GROC) scale at 3 and 12 months

3. Primary prognostic variables (collected at baseline):
3.1. Self-reported sensory profiling measured using the Neuropathic Pain Symptom Inventory (NPSI) and painDETECT questionnaires, and a body chart
3.2. Somatosensory profiling determined with the validated quantitative sensory testing protocol from the German Network for Neuropathic pain, and Conditioned Pain Modulation (CPM)
3.3. Psychosocial profile established through the Patient-Reported Outcomes Measurement Information System (PROMIS for anxiety, depression, fatigue, sleep disturbance, instrumental support, emotional support, ability to participate in social roles and activities), Adverse Childhood Events (ACEs), prolonged hospitalisation for a life-threatening condition (single question with yes/no answer), Pain Catastrophizing Scale (PCS), Ten-Item Personality Index (TIPI), State Optimism Measure (SOM-7), Sciatica Perception Questionnaire (SPQ), Stigma Scale for Chronic Illnesses (SSCI), and International Physical Activity Questionnaires (IPAQ)
3.4. Blood inflammatory markers measured using protein and metabolomic analyses

Additional phenotypic data assessed at baseline:
1. Demographic and medical information
2. Clinical examination
3. Self-reported questionnaires:
3.1. Prognostic indicators measured using the STarT Back Screening Tool
3.2. Health-related quality of life measured using the EuroQol EQ-5D questionnaire
3.3. Pain severity measured using a diary
3.4. Micro and macrostructural changes of lumbar nerve roots measured using magnetic resonance neurography in a subset of ~100 patients and ~50 healthy controls
Overall study start date01/01/2018
Completion date30/09/2025

Eligibility

Participant type(s)Healthy volunteer, Patient
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participants180
Total final enrolment229
Key inclusion criteria1. People aged >18 years with a clinical diagnosis of ‘sciatica’
2. Sciatica symptom onset of the current episode within the past 3 months with a symptom-free period of at least 3 months preceding the current sciatica symptoms
3. A sum score of >4 (on the diagnostic model published by Stynes 2018) will be defined as sciatica (weighted sum score including self-reported sensory changes, below knee pain, leg pain worse than back pain, neurodynamic tests, and neurological deficit)
4. Clinical examination confirms the clinical diagnosis of sciatica and rules out other diagnoses
Key exclusion criteria1. Presence of other nerve-related disorders (e.g. diabetic neuropathy, stroke)
2. Previous lumbar spine surgery
3. Serious spinal pathologies (e.g. infection, cauda equina syndrome, metastatic lesions)
4. Chronic inflammatory disorders
5. Other pain conditions that may confound assessment (e.g., fibromyalgia)
6. Pregnancy
7. Insufficient command of the English language to obtain consent/complete questionnaires
8. Contraindications to MRI for those selected for scanning
Date of first enrolment15/05/2022
Date of final enrolment23/09/2024

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

Oxford University
Nuffield Department of Clincial Neurosciences
John Radcliffe Hospital
West Wing Level 6
Oxford
OX39DU
United Kingdom

Sponsor information

University of Oxford
University/education

Clinical Trials and Research Governance
Joint Research Office
Block 60
Churchill Hospital
Headington
Oxford
OX37LE
England
United Kingdom

Phone +44 (0)1865 616480
Email ctrg@admin.ox.ac.uk
Website http://www.ox.ac.uk/
ROR logo "ROR" https://ror.org/052gg0110

Funders

Funder type

Government

UK Research and Innovation
Government organisation / National government
Alternative name(s)
UKRI
Location
United Kingdom
Versus Arthritis
Private sector organisation / Other non-profit organizations
Location
United Kingdom
National Institute for Health and Care Research
Government organisation / National government
Alternative name(s)
National Institute for Health Research, NIHR Research, NIHRresearch, NIHR - National Institute for Health Research, NIHR (The National Institute for Health and Care Research), NIHR
Location
United Kingdom

Results and Publications

Intention to publish date13/05/2026
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryStored in publicly available repository
Publication and dissemination plan1. Planned publication in a high-impact peer-reviewed journal
2. Conference presentations
3. Social media
4. Co-productions with patient partners such as videos, and interviews.
IPD sharing planThe datasets generated during and/or analysed during the current study will be stored in a publicly available repository (Alleviate/ https://alleviate.ac.uk)

• The type of data that will be shared: All data presented in the final manuscript and outlined in the protocol.
• Dates of availability: expected to be available after publication of the main papers.
• Whether consent from participants was required and obtained: yes
• Comments on data anonymization: data will be anonymised
• Any ethical or legal restrictions: Data sharing agreements with Alleviate data hub are already in place.
• Any additional comments? For more information on Alleviate hub, see https://alleviate.ac.uk

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Protocol article 05/04/2023 06/04/2023 Yes No
HRA research summary 28/06/2023 No No

Editorial Notes

01/10/2024: The following changes were made to the study record:
1. The recruitment end date was changed from 30/08/2024 to 23/09/2024.
2. The overall study end date was changed from 30/08/2025 to 30/09/2025.
3. Total final enrolment added.
23/05/2024: The following changes were made to the trial record:
1. The recruitment end date was changed from 15/05/2024 to 30/08/2024.
2. The overall end date was changed from 13/05/2025 to 30/08/2025.
3. The plain English summary was updated to reflect these changes.
06/04/2023: Publication reference added.
10/02/2023: Trial's existence confirmed by NHS HRA.