Table 1.
Characteristics of included meta-analyses of observational studies, or non-randomised studies
| Author, year | k | Population (age) | Type of cannabinoid exposure* | Outcomes | Quality |
|---|---|---|---|---|---|
| Asbridge, 201222 | 9 | General population (adolescents, adults) | THC | Car crash death or injuries | Moderate |
| Bhagavan, 202064 | 5 | Insomnia (adults) | CBM | Sleep quality or quantity | High |
| Blest-Hopley, 201975 | 12 | General population (adolescents, adults) | Regular cannabis use | Brain executive and default mode network | Moderate |
| Bogaty, 201886 | 14 | Psychosis (adolescents, adults) | Cannabis current use | Cognition | Moderate |
| Borges, 201697 | 16 | General population (adolescents, adults) | Cannabis use | Suicide ideation, attempt, and suicide | Moderate |
| Burns, 201298 | 9 | First episode psychosis (adolescents, adults) | Cannabis use | Duration of untreated psychosis | Low |
| Chisini, 201999 | 4 | General population (adolescents, adults) | Cannabis use | Periodontitis | Low |
| Conner, 2016100 | 31 | Pregnant women (adult) | Marijuana use | Low birth weight | Moderate |
| De Carvalho, 2015101 | 6 | General population (adolescents, adults) | Marijuana use | Head and neck cancer | Moderate |
| Escelsior, 202154 | 16 | General population (adolescents, adults) | Cannabinoids | Self-injurious behaviour | Low |
| Farooqui, 201955 | 9 | HCV+NAFDL (adult) | Marijuana use | Liver fibrosis | Moderate |
| Foglia, 201756 | 15 | Psychosis (adolescents, adults) | Cannabis use (current, past) | Antipsychotics adherence | High |
| Ghasemiesfe, 201921 | 25 | General population (adults) | Marijuana ever use, use >10 year | Cancer (lung, head and neck, oral, testicular) | High |
| Ghasemiesfe, 201857 | 22 | General population (adolescents, adults) | Marijuana use | Sputum production and cough | High |
| Gibbs, 201558 | 6 | General population (adult) | Cannabis use | Mania symptoms | Moderate |
| Goldenberg, 201759 | 20 | Mixed medical conditions† (adult) | Cannabis, cannabinoids | Health related quality of life | Moderate |
| Grant, 200260 | 11 | General population (adult) | Cannabis use | Cognition | Moderate |
| Gunn, 201661 | 6 | Pregnant women (adult) | Cannabis use | Maternal anaemia | Moderate |
| Gurney, 201562 | 3 | General population (adults <50) | Cannabis use, current | Testicular cancer, non-seminoma | Moderate |
| Hostiuc, 201863 | 24 | General population (adolescents, adults) | Cannabis use | Car events | Moderate |
| Johnson, 201765 | 13 | General population (adolescents, young adults) | Cannabis use | Physical dating violence | High |
| Kamp, 201866 | 5 | General population (adults) | Cannabis use | Dopamine receptors, transporter and synthesis | Moderate |
| Kiburi, 202167 | 18 | General population (adolescent) | Cannabis use | Psychosis | High |
| Kraan, 201668 | 7 | Ultra-high risk of psychosis (adolescents, adults) | Cannabis use | Psychosis (transition to) | High |
| Lev-Ran, 201469 | 14 | General population (adolescents, adults) | Cannabis use (normal, heavy) | Depression | High |
| Lorenzetti, 201970 | 30 | General population (adolescents, adults) | Regular cannabis use | Brain volume | High |
| Marchand, 202271 | 16 | Pregnant women (adults) | Marijuana use | Low birth weight, small for gestational age, preterm delivery, NICU, Apgar, head circumference | Low |
| Moore, 200772 | 35 | General population (adolescents, adults) | Cannabis use | Depression, psychosis symptoms and suicidal ideation | Moderate |
| Myles, 201273 | 38 | General population (adolescents, adults) | Cannabis use | Age at onset of schizophrenia and other psychoses | Moderate |
| Noori, 202174* | 12 | Chronic pain on opioids | Cannabis use | Opioid use | Low |
| Power, 202176 | 7 | General population (adolescents, young adults) | Cannabis use, frequent/dependent | IQ, verbal IQ | High |
| Rabin, 201177 | 8 | Schizophrenia (adults) | Cannabis use | Cognition | Low |
| Rocchetti, 201378 | 14 | General population (adolescents, adults) | Cannabis use | Hippocampal volume | Moderate |
| Rodriguez-Almaraz, 202079 | 5 | Malignant CNS tumours (adults) | Cannabis use | Survival | Low |
| Rogeberg, 201980 | 12 | Drivers (adult) | Cannabis, THC positive | Car crush and car crush culpability | Low |
| Ruisch, 201881 | 36 | Pregnant women (adult) | Cannabis use | Offspring conduct problems | Moderate |
| Ruiz-Veguilla, 201282 | 5 | Psychosis (adolescents, adults) | Cannabis use | Neurological soft signs | Moderate |
| Sabe, 202083 | 20 | Schizophrenia (adults) | Cannabis use | Negative symptoms | High |
| Sánchez-Gutiérrez, 202084 | 7 | First-episode psychosis (adolescents, adults) | Cannabis use | Cognition | Low |
| Schoeler, 201685 | 24 | Psychosis | Cannabis use (continued, past) | Psychosis, relapse | Moderate |
| Schoeler, 201687 | 88 | Healthy subjects, psychosis (adult) | Cannabis use | Cognition | Low |
| Schreiner, 201288 | 33 | General population (adolescents, adults) | Cannabis use (past) | Cognition | Critically low |
| Schumacher, 201889 | 11 | General population (adolescent, adult) | Cannabis | Condom use | Moderate |
| Scott, 201890 | 69 | General population (adolescent, adult) | Cannabis (current, past) | Cognition | High |
| Smith, 201491 | 11 | General population (adolescents, adults) | Cannabis (heavy use) | Behavioural inhibition | Moderate |
| Sultan, 201892 | 13 | General population (not reported) | THC | Heart rate change | Moderate |
| Szoke, 201493 | 29 | General population (adult) | Cannabis use | Schizotypy | Moderate |
| Wijarnpreecha, 201894 | 3 | HCV (adult) | Cannabis use | Advanced liver fibrosis | High |
| Xue, 202195 | 10 | General population (adolescents, adults) | Cannabis use | Anxiety | Low |
| Zhang, 201596 | 6 | General population (adult) | Cannabis use | Lung cancer | Low |
CBM=cannabis based medications; CNS=central nervous system; HCV=hepatitis C virus; IQ=intelligent quotient; k=number of studies included in the overall eligible systematic review with meta-analysis; NAFLD=non-alcoholic fatty liver disease; NICU=admission to neonatal intensive care unit; THC=tetrahydrocannabinol.
*
Included both observational studies and randomised controlled trials.
†
Fibromyalgia, HIV, inflammatory bowel disease, and neuropatic pain.