Evidence map›Paper›PMID 33469735›Full record

Observational studyCanadian journal of anaesthesia = Journal canadien d'anesthesie2021

Patient-reported outcomes in those consuming medical cannabis: a prospective longitudinal observational study in chronic pain patients.

Howard Meng, M Gabrielle Page, Prabjit Ajrawat, Amol Deshpande, Bana Samman, Mary Dominicis, Karim S Ladha, Joseph Fiorellino, Alexander Huang, Yuvaraj Kotteeswaran and 3 more

Abstract readObservational Study
PubMed Publisher
In one paragraph

Observational study in Canadian journal of anaesthesia = Journal canadien d'anesthesie, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 18 papers, 2 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
18citing papers in PubMed, 2 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

18 citing papers in PubMed, 2 syntheses or guidelines pooled it.

  1. Health-related quality of life in patients receiving medicinal cannabis: systematic review and meta-analysis of primary research findings 2015-2025.Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation · 2026
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  10. Shifts in medical cannabis use in Canada during the COVID-19 pandemic.Health promotion and chronic disease prevention in Canada : research, policy and practice · 2023
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  14. Comment on: Cannabis use among Danish patients with cancer: a cross‑sectional survey of sociodemographic traits, quality of life, and patient experiences.Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer · 2022
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4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

13 authors.

Howard MengDepartment of Anesthesiology and Pain Medicine, University of Toronto, Toronto, ON, Canada.
M Gabrielle PageCentre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Département d'anesthésiology et médecine de la douleur, Faculté de médecine, Université de Montréal, Montreal, QC, Canada.
Prabjit AjrawatDepartment of Anesthesia, Toronto General Hospital, Toronto, ON, Canada.
Amol DeshpandeToronto Rehabilitation Institute, Toronto, ON, Canada.
Bana SammanDepartment of Anesthesia, Toronto General Hospital, Toronto, ON, Canada.
Mary DominicisDepartment of Anesthesia, Toronto General Hospital, Toronto, ON, Canada.
Karim S LadhaDepartment of Anesthesia, St. Michael's Hospital, Toronto, ON, M5B 1W8, Canada.
Joseph FiorellinoDepartment of Anesthesiology and Pain Medicine, University of Toronto, Toronto, ON, Canada.
Alexander HuangDepartment of Anesthesiology and Pain Medicine, University of Toronto, Toronto, ON, Canada.
Yuvaraj KotteeswaranDepartment of Anesthesia, Northern Ontario School of Medicine, Thunder Bay, ON, Canada.
Alex McClaren-BladesDepartment of Anesthesiology and Pain Medicine, University of Toronto, Toronto, ON, Canada.
Lakshmi P KotraCentre For Cannabinoid Therapeutics, Toronto, ON, Canada.
Hance ClarkeDepartment of Anesthesiology and Pain Medicine, University of Toronto, Toronto, ON, Canada. hance.clarke@uhn.ca.ORCID http://orcid.org/0000-0003-4975-3823

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeWe investigated patients with chronic pain seeking medical cannabis. We assessed their demographics, patterns of cannabis use, and the long-term effectiveness of cannabis on their pain and functional domains.

methodsThis observational study enrolled patients between 8 September 2015 and 31 July 2018 from community-based cannabis clinics in Ontario, Canada. In addition to collecting demographic information, the primary outcomes studied were pain intensity and pain-related interference scores assessed at baseline, three, six, and 12 months. Using validated questionnaires, we also assessed anxiety, depression, quality of life (QoL), general health symptoms, neuropathic pain, self-reported opioid consumption, and adverse events.

resultsOf the 1,000 patients consented, 757 (76%) participated at one or more of the study time points. At six and 12 months, 230 (30.4%) and 104 (13.7%) of participants were followed up, respectively. Most participants were female (62%), Caucasian (91%), and sought cannabis for pain relief (88%). Time was a significant factor associated with improvement in pain intensity (P < 0.001), pain-related interference scores (P < 0.001), QoL (P < 0.001), and general health symptoms (P < 0.001). Female sex was significantly associated with worse outcomes than male sex including pain intensity (P < 0.001) and pain-related interference (P < 0.001). The proportion of individuals who reported using opioids decreased by half, from 40.8% at baseline to 23.9% at 12 months.

conclusionDespite significant challenges to collecting long-term observational data on patients who attempted a trial of cannabis products, approximately one-third of patients in the cohort remained on medical cannabis for six months. In this cohort, pain intensity and pain-related interference scores were reduced and QoL and general health symptoms scores were improved compared with baseline.

Indexed as

Chronic PainMedical MarijuanaFemaleHumansMaleOntarioPatient Reported Outcome MeasuresProspective StudiesQuality of LifeMedical Marijuana

Identifiers

PMID33469735

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.