title: Matters of Substance.
authors.forename: Roger
authors.initials: R
authors.lastname: Jones
mesh_terms: D004739:England / Q000453:epidemiology; D058006:General Practice / Q000379:methods*; D006801:Humans; D015995:Prevalence; D011785:Quality Assurance, Health Care / Q000458:organization & administration*; D019966:Substance-Related Disorders / Q000453:epidemiology / Q000534:rehabilitation*