Table 1 Newcastle-Ottawa quality assessment scale

Check list

Selection

 •How representative was the control group (lymph node dissection) in comparison with the general elderly population for transitional cell carcinoma of the upper urinary tract? (if yes, one point; no point, if the patients were selected or selection of group was not described)

 •How representative was the research group (non-lymph node dissection) in comparison with the elderly population for transitional cell carcinoma of the upper urinary tract? (if data from the same community as the control group, one point; no point, if drawn from a different source or selection of group was not described)

 •Assignment for treatment: any detail report? (if yes, one point)

Comparability

 •Group comparable for the grade of tumor, clinical TNM staging system (if yes, two points; one point was assigned, if one of these two characteristics had differences; no star was assigned, if the two groups differed)

 •Group comparable for age, gender (if yes, two points; one star was assigned, if one of these two characteristics had differences; no point was assigned, if the two groups differed)

Outcome assessment

 •Comprehensively evaluated the outcome? (yes, one point for information ascertained by record or International Classification of Diseases; no point, if this information was not reported)

 •Adequacy of follow-up (one star, if follow-up > 90%)