Moriarty 1999.

Study characteristics
Methods	Allocation: randomised Blindness: double‐blind, double‐dummy Duration: 6 days (with run‐in period of 1–3 days) Funding: Napp Laboratories Ltd Setting: not stated. Unclear if these were inpatients or community patients Design: cross‐over
Participants	Diagnosis: people with cancer pain n = 100 Age: not stated Sex: 53 men; 47 women Cancer stage: not reported History: most common of primary malignancies presented by participants were lung, breast, gastrointestinal and genitourinary Inclusion criteria: people aged ≥ 18 years, with cancer and achieving pain control with CR morphine sulphate Exclusion criteria: significant respiratory depression; severe renal or hepatic impairment; taking strong opioid analgesics other than 12‐hourly morphine sulphate; taking monoamine oxidase inhibitors currently or within the previous 2 weeks; pregnant (or not adequately protected from becoming pregnant) or lactating women Consent: no details
Interventions	Hydromorphone CR 4 mg Morphine CR 30 mg
Outcomes	Pain VAS Adverse events Treatment preference Use of rescue medication
Notes	No pre‐cross‐over data available. No contact details available to request necessary information. We are also unclear about the intensity of people's cancer pain. This review only intended to include people with moderate to severe cancer pain.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "… according to a randomisation schedule previously prepared by the clinical supplies department at Napp Laboratories Limited …" Comment: third‐party randomisation used and was likely to be at low risk of bias.
Allocation concealment (selection bias)	Low risk	Third‐party randomisation used, thus we considered allocation concealment was likely to have been done.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Matched placebos were taken throughout to maintain the blinding of the study (double‐dummy technique)."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Although the outcome assessment was not reported, as most of the outcomes were participant‐reported, we rated this item at low risk of bias.
Incomplete outcome data (attrition bias) All outcomes	Low risk	11 people left the study early and were not included in the final analysis. Although the dropout rate was marginally > 10%, it is unlikely to have had a biased effect on the results, as reasons and proportion for dropout were given and comparable between groups.
Selective reporting (reporting bias)	Low risk	No protocol registration information provided. All outcomes in the method section were reported.
Other bias	High risk	Notable concerns: pharmaceutical company‐funded; 1 study author was an employee of Napp Laboratories Ltd, a pharmaceutical company that produces analgesics.