euCPSP: European Observational Study on Chronic Post Surgical Pain,PAIN-OUT Study (PAIN-OUT)

The main goal of the study is to obtain a generalizable epidemiology of chronic post surgical pain (CPSP) by performing a large data collection in many European countries. The large sample will allow analysis of the incidence of CPSP, differences in incidence patterns in Europe, incidence in rare types of surgeries and specific populations. This observational, prospective study will help to better anticipate and potentially prevent the development of chronic post surgical pain (CPSP). In fact when CPSP occurs patients are frequently undiagnosed and pain is poorly managed such that patients may develop refractory chronic pain. Surgery is a major cause of chronic pain and it is unique in that there is potential to prevent it from occurring. Data from this study might alert respectively surgeons and anesthetists about the most important types of surgery and some perioperative techniques of pain prevention with an impact on the incidence of chronic post surgical pain(CPSP). Anesthesiologists, who are leading this project, might therefore, have an important role in preventing future cases of chronic post surgical pain (CPSP).

Sample size calculation:

The investigators expect that at least 30 sites will be able to participate and recruit 200 patients a year, to a maximum of 6,000 patients, over the one year study period. Since the mean incidence of CPSP is approximately 30%, this will offer an estimated potential number of 2000 patients with CPSP.

Organisation:

Investigators will use questionnaire in English, German, French, Spanish, Italian, Romanian, Swedish, Hebrew, Dutch and Russian. They will supervise data collection, ensure timely data return and act as guarantor for the integrity and quality of data collected.

The Chief investigator, Professor Fletcher is a member of the PAIN OUT group and will closely work with the new group of investigators participating in the project on CPSP. His experience with the European PAIN OUT project will be very valuable to organize and coordinate the study. The European Society of Anaesthesiology (ESA) is supporting this project and will help with administrative coordination to build the European network.

Time scale:

The study will last two and a half years with one year for recruitment, one year for follow up and 6 months for analysis.

Statistical Analysis:

Incidence of chronic post surgical pain (CPSP) at 12 months for all types of surgeries analyzed will be expressed as mean and confidence interval 95%. The investigators will compare the incidence in various types of surgeries, different centres and countries.

Risk factors of chronic post surgical pain (CPSP) will be analyzed using univariate and multivariate analysis. The most predictive factors will be chosen by fitting a logistic regression model using a forward selection procedure. By combining data from different centres, the investigators will determine most significant risk factors.