Huse 2001.

Study characteristics
Methods	Randomised, cross‐over, 4‐week double‐blinded phase with 1 to 2 weeks' wash‐out period; a long‐term open phase for responders to intervention; physician with no contact with participants randomised and kept code Ff‐up: hourly for pain and adverse event; weekly during 4 weeks of DB phase; long term 6, 12 mos (open)
Participants	Phantom pain at least 3 in 10‐centimetre VAS; with upper and lower extremity amputations; 12 participants, 10 males; mean age, yrs (SD): 50.58 (14.01); mean baseline pain intensity on 10‐centimetre VAS (SD): 4.65 (1.06); time since amputation, years (SD): 16.49 (14.01)
Interventions	morphine sulfate titrated from 70 mg/day up to 300 mg/day or max tolerable dose for 4 weeks, oral placebo
Outcomes	Change in pain intensity on 0‐to‐10‐centimetre VAS; Number of participants with pain reduction of > 50% (10‐centimetre VAS); Change in mood/depression on Self‐Rating Depression Scale; Long‐term outcomes (6 months, 12 months): only with morphine sulfate; n = 9 Other outcomes: pain‐related self‐assessment scale; active coping and catastrophising using West Haven‐Yale Multidimensional Pain Inventory; Brief Stress Scale; psychophysical thresholds, 2‐point discrimination; attentional performance with d2 Test of Attention, magnetoencephalography
Notes	Small sample size (n = 12); cortical reorganisation results based on 3 participants (open phase)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Low risk	Physician with no contact with participants randomised and kept code.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Described as a double‐blind study; efforts were made to blind participants (e.g. treatment and placebo preparations were "put into exactly identical pills by the pharmacy"; identical treatment phases). The authors of the study acknowledged in their discussion that the participants were able to guess the morphine medication (but not the placebo) due to side effects, but there was no mention of feedback as to the correctness of their guess. Also, pain reduction scores with the morphine treatment were not significantly correlated with participant‐assessed treatment expectancy outcomes.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Described as double‐blind study; while there was mention of psychologist (not involved in giving treatment to the participant) who administered psychological assessment scales, it was unclear who assessed pain intensity and side effects
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants accounted for in analysis of outcomes
Selective reporting (reporting bias)	Low risk	All specified outcomes in methods section of published study were reported, although not necessarily as our preferred outcomes.
Other bias	Low risk	(+) wash‐out period
Size of study	High risk	n = 12