Is the aim of the study clearly described?	Are the main outcomes to be measured clearly described in the introduction or methods section?	Bias due to confounding	Is confounding of the effect of intervention unlikely in this study?	Bias in selection of participants into the study	Did the authors describe how the population was selected?	Was selection into the study unrelated to intervention or outcome?	Are the characteristics of the population included in the study clearly described?	Did start of intervention and follow-up coincide for most subjects?	Bias in measurement of intervention	Is intervention well described?	Was information on intervention status recorded at the time of intervention?	Was information on intervention status unaffected by knowledge of outcome?	Bias due to missing data	Was intervention status complete for subjects in the intervention group	Were the characteristics of subjects lost to follow-up described?	Are outcome data complete?	Bias in measurement of outcomes	Was the outcome measure objective?	Were the statistical tests used to assess the main outcomes appropriate?	Are the findings presented clearly, objectively, and in sufficient detail to enable the reader to judge the results for himself/herself?	Did the investigators consider all possible logical interpretations of their results?
Bauman	Y	Y		N		Y	U	N	Y		Y	Y	Y		Y	U	Y		N	U	N	Y
Hawton	Y	Y		N		Y	U	Y	U		Y	Y	Y		Y	Y	N		N	Y	Y	Y
Johnson	Y	Y		N		Y	U	U	Y		Y	Y	Y		Y	Y	Y		N	U	U	U