Study designs of evaluations included in the review
No restrictions were made on the study design of trials included in the review. All studies identified were case series (both prospective and retrospective).
Studies had to provide information on the instruments used to evaluate analgesia, and data to calculate the proportion of patients achieving adequate analgesia.
Specific interventions included in the review
WHO analgesic ladder for cancer pain management.
Participants included in the review
Patients receiving cancer pain treatment according to the steps and principles recommended in the original WHO analgesic ladder.
Outcomes assessed in the review
The percentage of patients receiving adequate analgesia. Analgesia was defined to be adequate if pain relief had been measured and patients had reported it to be adequate, satisfactory, acceptable, good or complete, or if it had been given more than 70% of the maximum score on a visual analogue scale. If pain intensity was the only measure reported, analgesia was defined as adequate if patients had reported pain intensity as none, slight or mild, or had scored a reduction of more than 70% using a visual analogue scale.
How were decisions on the relevance of primary studies made?
The authors do not state how the papers were selected for the review, or how many of the authors performed the selection.