2.5. Summary of evidence

The patient representative was involved in defining the key questions, providing recommendations and good clinical practice statements, and the evaluation of the patient version of the clinical practice recommendations.

The evidence synthesis team created evidence summaries based on the selected systematic reviews. The selection of outcomes of interest was based on the recommendations of the ACTINPAIN writing group of the International Association for the Study of Pain's (IASP) Special Interest Group on Systematic Reviews in Pain Relief (Moore et al., 2010) and the guideline on the clinical development of medicinal products intended for the treatment of pain of the European Medicines Agency (2017). These outcomes included:

Pain relief from baseline of 30% or greater

Patient global impression to be much or very much improved

Disability

Drop out rates to adverse events

Serious adverse events

Death

Non‐medical use/dependence

We used the systematic review with the most recent search of literature or the most studies included in the analyses. If reported, the GRADE system was used for the evidence summaries to provide a description of benefits and harms, along with a rating of the certainty of the evidence on an outcome‐by‐outcome basis (Langendam et al., 2013). If no GRADE rating was available, we used the UpToDate® rating of the quality of evidence (UptoDate, 2020a, 2020b).

Pain Alliance Europe (PAE) conducted a survey with some member countries (Spain, Romania, Belgium, UK, Sweden and Finland) on the importance of potential positive and negative effects taking a new medication for the chronic pain management from 22 May to 2 June 2020. The potential positive and negative effects of medications (related to opioids) were selected by three TF members (two physicians, one patient representative). In total, 131 PAE members participated (78% females). The details of the patient survey are outlined in Supplementary Material 2. Important or very important positive and negative effects were rated as follows:

Positive effects

Pain relief of 50% or more: 74% of the respondents.

Pain relief of 30% or more: 92% of the respondents.

Improvement of daily functioning: 91%.

Improvement of sleep: 82%.

Negative effects

Somnolence: 66%.

"Addiction": 58%.

Sexual problems: 45%.

In addition, a search in PubMed [‘patient preferences’ AND ‘opioids’ AND ‘CNCP’) in 6 February 2020 produced 6 hits. We found one systematic review, which ranked pain relief, nausea and vomiting as highly significant negative outcomes across studies. When considered in the studies, the adverse effect of personality changes was rated as equally important. Constipation was assessed in most studies and was an important outcome, but secondary to pain relief, nausea and vomiting. The only two studies that evaluated addiction, found it less important to patients than pain relief (Goshua et al., 2018).