Table 3.
The number of studies identified for different treatments
| Number of studies | ||||
| Assessment Item | Yes | No | Unable to judge | Not applicable |
| Clarity of study question and definition of outcome | ||||
| Is the purpose of the study clearly stated? | 8 | 1 | 1 | - |
| Is the definition of prosthesis failure clear? | 7 | 2 | - | 1 |
| Is there a clear definition of primary outcome(s)? | 7 | 3 | - | - |
| Are standardised outcome measures used? | 9 | - | 1 | - |
| Are the outcome measures used appropriate for the purpose of the study? | 9 | 1 | - | - |
| Description of prosthesis and method of fixation | ||||
| Is the prosthesis design adequately described? | 7 | 2 | - | 1 |
| Is the method of fixation adequately described? | 7 | 2 | - | 1 |
| Description of study sample | ||||
| Is the method of selection of the sample adequately described? | 2 | 7 | 1 | - |
| Are the study exclusion and inclusion criteria stated? | 2 | 7 | 1 | - |
| Is the baseline sample clearly described in terms of basic characteristics (age, sex etc)? | 6 | 3 | 1 | - |
| Is the study sample sufficiently homogenous in terms of disease/diagnosis? | 5 | 1 | 4 | - |
| Is the study sample sufficiently homogenous in terms of co-morbidity? | 2 | - | 8 | - |
| Control of bias in study design | ||||
| Is the method of randomisation adequate? | - | - | 1 | 9 |
| Is the method of masking the patient to the intervention allocated stated? | - | 2 | 1 | 7 |
| Were outcome assessors blind to intervention allocation? | - | 1 | 3 | 6 |
| Are baseline values for groups compared? | - | 1 | 1 | 8 |
| Has the study adequately controlled for confounding factors? | 1 | 7 | 2 | - |
| Duration and completeness of follow-up | ||||
| Are intervals between surgery and follow-up assessment clearly stated? | 8 | 2 | - | - |
| Are reasons for loss of patients at follow-up stated? | 2 | 2 | 2 | 4 |
| Are those lost to follow-up compared to the rest of the sample? | 1 | 2 | 3 | 4 |
| Is there an appropriate length of follow-up? | 8 | 2 | - | - |
| Is the length of follow-up at least 5 years? | 3 | 7 | - | - |
| Statistical and analytical considerations | ||||
| Has the study sample size been justified? | - | 9 | 1 | - |
| Are the data clearly presented? | 8 | 2 | - | - |
| Was the data analyst masked to interventions? | - | 5 | 3 | 2 |
| Has type of statistical test and actual probability value been stated? | 2 | 1 | 1 | 6 |
| Are statistical tests appropriate to study? | 2 | - | 2 | 6 |
| Is the sample on which failures are assessed adequate? | - | 2 | 7 | 1 |
| Are conclusions justified by evidence? | 5 | 1 | 3 | 1 |