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Table 5 Detailed assessment of study quality

From: N-of-1 trials in the clinical care of patients in developing countries: a systematic review

Author (date)

Sources of risk of bias

Selection bias

(random sequence generation)

Selection bias

(allocation concealment)

Reporting bias

(incomplete outcome data)

Reporting bias

(selective reporting)

Performance bias

(blinding of participants and clinicians)

Inadequate cycles

(risk of error – especially type 2)

Appropriateness of treatment for design

Appropriate washout period

Huang, et al., (2014) [32]

Low

Method of random sequence generation is describe.

Low

Independent pharmacist assigned treatments

Low

All outcome data are reported

Low

All outcome data are reported

Low

Method of blinding is adequately described

Low

3 cycles were conducted

Unclear

Biochemical and pharmacokinetic information of the TM is not known

Low risk

Adequate washout period based on preliminary study

Yuhong, et al., (2012) [33]

Low

Method of random sequence generation is described

Low

Independent pharmacist assigned treatments

Low

Acceptable reasons for missing data are given

Low

All outcome data are reported

Unclear

Method of blinding is not adequately described

Low

3 cycles were conducted

Unclear

Biochemical and pharmacokinetic information of the TM is not known

High

2 days of washout period decided speculatively

Wang et al., (2010) [35]

Low

Method of random sequence generation is described

Low

Independent pharmacist assigned treatments

Low

Acceptable reasons for missing data are given

Low

All outcome data are reported

Low

Method of blinding is adequately described

Low

3 cycles were conducted

Unclear

Biochemical and pharmacokinetic information of the TM is not known

High

The length of washout period is not well justified

Yu, et al., (2012) [36]

Low

Method of random sequence generation is described

Unclear

The independence of the person who assigned treatments is not well described

Low

All outcome data are reported

Low

All outcome data are reported

High

Method of blinding is not adequately described

Low

3 cycles were conducted

Unclear

Biochemical and pharmacokinetic information of the TM is not known

High

The length of washout period is not well justified

Zhang, et al., (2012) [37]

Low

Method of random sequence generation is described

Unclear

The independence of the person who assigned treatments is not well described

Low

All outcome data are reported

Low

All outcome data are reported

High

Method of blinding is not adequately described

Low

3 cycles were conducted

Unclear

Biochemical and pharmacokinetic information of the TM is not known

High

The length of washout period is not well justified

Louly, et al., (2009) [34]

Low

Method of random sequence generation is described

Low

Treatment assigned by a researcher who had no contact with the patient or result

Low

All outcome data are reported

Low

All outcome data are reported

Low

Method of blinding is adequately described

Low

3 cycles were conducted

Low

The design is suitable for tramadol

Low

Adequate washout period

  1. TM trial medication