+1 Recommend
1 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Recruitment and inclusion procedures as “pain killers” in clinical trials?

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.



          Recruitment and inclusion procedures in clinical trials are time critical. This holds particularly true for studies investigating patients with fluctuating symptom patterns, like those with chronic neck pain. In a feasibility study on neck pain, we found a clinically relevant decrease in pain ratings within the recruitment period. This paper analyses the phenomenon and gives recommendations for recruitment procedures in clinical trials on pain.


          Changes in pain intensity scores of 44 chronic neck pain patients (6 males and 36 females; mean age: 45.3±13.2 years) between the first telephone contact and baseline assessment were analyzed. Inclusion criterion was a mean pain intensity of ≥40 on a 0–100 numerical rating scale during the last three months. Statistical analyses were performed using ANOVA and parametric/non-parametric correlation coefficients.


          Average pain intensity score decreased significantly from 60.3±13.3 at telephone interview to 38.1±21.7 at baseline assessment. This represents a relative change of 36.8%. A weak but significant negative correlation was found between number of days between assessments and pain rating differences. There was a positive correlation between change of pain intensity and the pain level at the first contact, indicating that the decreased pain ratings over time were also dependent on the initial pain rating.


          The clinically significant changes in pain intensity were weakly related to waiting time and moderately dependent on initial pain intensity, suggesting regression to the mean. The natural course of the disease and the Hawthorne effect are also discussed as contributing factors.

          Related collections

          Most cited references 21

          • Record: found
          • Abstract: not found
          • Article: not found

          The Hawthorne effect: A reconsideration of the methodological artifact.

           John G. Adair (1984)
            • Record: found
            • Abstract: found
            • Article: not found

            New insights into the placebo and nocebo responses.

            In modern medicine, the placebo response or placebo effect has often been regarded as a nuisance in basic research and particularly in clinical research. The latest scientific evidence has demonstrated, however, that the placebo effect and the nocebo effect, the negative effects of placebo, stem from highly active processes in the brain that are mediated by psychological mechanisms such as expectation and conditioning. These processes have been described in some detail for many diseases and treatments, and we now know that they can represent both strength and vulnerability in the course of a disease as well as in the response to a therapy. However, recent research and current knowledge raise several issues that we shall address in this review. We will discuss current neurobiological models like expectation-induced activation of the brain reward circuitry, Pavlovian conditioning, and anxiety mechanisms of the nocebo response. We will further explore the nature of the placebo responses in clinical trials and address major questions for future research such as the relationship between expectations and conditioning in placebo effects, the existence of a consistent brain network for all placebo effects, the role of gender in placebo effects, and the impact of getting drug-like effects without drugs.
              • Record: found
              • Abstract: found
              • Article: not found

              What Happened at Hawthorne?: New evidence suggests the Hawthorne effect resulted from operant reinforcement contingencies.

               Loren Parsons (1974)
              The Hawthorne effect in experimental research is the unwanted effect of the experimental operations themselves. Following the Hawthorne studies, various explanations have been proposed to account for rising rates of production. Although in the Relay Assembly Test Room experiment the experimental operations may have produced other extraneous variables, a reexamination based on new and neglected evidence has yielded a new interpretation. The new variable, made more plausible because research in other contexts has shown it to have similar effects, is a combination of information feedback and financial reward. It is an example of the control of behavior by its consequences. Although several approaches may be taken to explain the effects of response-consequence contingencies, I have favored operant conditioning because it seems to account for progressive increases in response rate-the Hawthorne phenomenon. Generalizing from the particular situation at Hawthorne, I would define the Hawthorne effect as the confounding that occurs if experimenters fail to realize how the consequences of subjects' performance affect what subjects do. But the Hawthorne effect need not be viewed solely as a problem in conducting experiments. The phenomenon that created it should be studied in its own right, as Sommer (67) suggested with a different phenomenon in mind. The study of response-consequence contingencies might well be extended to the examination of motivation in industrial workers.

                Author and article information

                J Pain Res
                J Pain Res
                Journal of Pain Research
                03 July 2019
                : 12
                : 2027-2037
                [1 ]Department of Sports Medicine and Health Promotion, Friedrich Schiller University Jena , Jena, Germany
                [2 ]Department of Psychiatry and Psychotherapy, Jena University Hospital , Jena, Germany
                [3 ]Department of Community Medicine, The National Research Center for Complementary and Alternative Medicine (NAFKAM), UiT The Arctic University of Norway , Tromsø, Norway
                [4 ]Crocker Institute , Kiawah Island, SC, USA
                [5 ]School of Integrative Medicine and Health Sciences, Saybrook University , Oakland, CA, USA
                [6 ]Pain clinic, University Hospital of Northern Norway, UiT The Arctic University of Norway , Tromsø, Norway
                [7 ]Department of Biological and Clinical Psychology, Friedrich Schiller University , Jena, Germany
                [8 ]Center for Interdisciplinary Prevention of Diseases related to Professional Activities, Friedrich Schiller University , Jena, Germany
                [9 ]Oregon Health & Science University , Portland, OR, USA
                Author notes
                Correspondence: H NothnagelDepartment of Sports Medicine and Health Promotion, Friedrich Schiller University Jena , Wöllnitzer Straße 42, Jena07749, GermanyTel +49 364 194 5647Fax +49 3641 945652Email helen.nothnagel@ 123456uni-jena.de
                © 2019 Nothnagel et al.

                This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License ( http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms ( https://www.dovepress.com/terms.php).

                Page count
                Figures: 6, Tables: 1, References: 34, Pages: 11
                Original Research


                Comment on this article