Can diagnostic uncertainty bias patients’ memory?

Our thoughts shape our emotional and behavioural responses. This is a well-established principle in psychological research and Cognitive Behavioural Therapy. We use preconceptions – known as “schemas” – to help us filter new and ambiguous information. These schemas are helpful in many ways, but they do not always serve us well: they will often produce biases in the way we process information, influencing our attention, memory and interpretation of new information. For instance, these preconceptions can lead us to pay more attention to negative than to positive health information. Such biases are thought to contribute to increased levels of distress and disability in chronic pain patients.

But not all pain patients have this tendency to process information in a biased way, so perhaps there are factors that make some patients more likely to show information processing biases. If so, what are these factors?

In this study, we specifically focused on chronic low back pain (LBP) patients[1]. We wanted to examine whether patients’ beliefs about their pain and diagnosis might be one factor that influences their vulnerability to information processing bias. In the majority of LBP patients, a clear diagnosis cannot be made, and as a result these patients are given unclear diagnostic labels, such as non-specific LBP. These patients often report feeling uncertain about their pain and diagnosis. There is evidence that diagnostic uncertainty can place an extra burden on these patients and can impact on how they feel and manage their pain [2]. For instance, they may feel that their pain is considered less legitimate and they may carry on searching for a diagnosis, instead on focusing on other, more important aspects of life.

In this study we wanted to examine if chronic LBP patients who are uncertain about their diagnosis process information differently to those who are certain of their diagnosis. To this end, we devised an experiment which enabled us to assess patients’ susceptibility to memory biases without the patients’ being completely aware of the aims of the experiment. Some of the patients were uncertain of their diagnosis and some were certain of their diagnosis, based upon what clinicians had told them, though all had simple mechanical low back pain.

We used a computer-based task in which patients were exposed to a number of pain, illness, depression and neutral words (all adjectives, e.g. sore, suffering, unlovable, obnoxious), which were randomized for each participant. Preceding each word was the cue question, ‘‘Does the following word describe you/ or you pain?’’, which facilitated encoding of the words in relation to the self. It was presented for three seconds, followed by a delay of 500 milliseconds, before the appearance of the target word. The participants were expected to respond to the target word by answering ‘yes’ or ‘no’ as quickly as they could, by pressing either right or left shit key on the keyboard. As soon as a response has been made or after 3500ms, the next cue question was presented. Reaction times were also measured to their responses by the computer. They were then asked to recall words in a surprise test later.

This experimental methodology has the benefit that participants are relatively free of self-awareness. The results showed that only the group with diagnostic uncertainty exhibited a memory bias for negative illness-related stimuli. Additionally, this group of patients had significantly higher levels of depression and disability.

Overall, the findings suggest that being uncertain of the meaning of one’s pain and diagnosis is associated with vulnerability to information processing biases, and might lead to increased distress and disability levels although the cross-sectional design of the study means that causality cannot be confidently inferred. The challenge for future research is to investigate whether these biases can be modified in order to improve outcomes in this group of LBP patients.

About Danijela Serbic

Danijela Serbic

Danijela Serbic is a PhD student at Royal Holloway, University of London, UK, under the supervision of Professor Tamar Pincus. The broad area of her research is the role of psychology in chronic pain. Her PhD research examines the impact of diagnostic status and diagnostic uncertainty on clinical outcomes (such as depression, anxiety and disability) in chronic low back pain patients. Danijela also works as a teaching associate in the Department of Psychology at Royal Holloway, where she is involved in the teaching and student assessment of psychological research methods and analysis, abnormal psychology and other undergraduate courses.

About Tamar Pincus

Tamar Pincus

Professor Tamar Pincus holds a PhD (University College London), as well as Masters degrees in experimental research methods in psychology (UCL), and epidemiology (Cambridge University). Her research has embraced a variety of methodologies, including experimental, epidemiological and qualitative. The research has included investigation of attention and recall in pain patients; the psychological predictors for poor outcome in low back pain, and the study of clinicians’ beliefs and attitudes in low back pain. Recently the focus of her research has moved to investigating the effectiveness of interventions through randomised controlled trials, and throughout she has collaborated closely with researchers from many disciplines, including doctors, physiotherapists, osteopaths, chiropractors and clinical psychologists, from a multitude of institutions, including Warwick, Keele, QMW, Leeds, Manchester, The British School of Osteopathy and many others. She also convened the international consensus group to establish what factors and measures should be included in prospective cohorts investigation the transition from early to persistent back pain. Most recently her research has focused on delivering effective reassurance to patients in primary care.


[1] Serbic D, & Pincus T (2014). Diagnostic uncertainty and recall bias in chronic low back pain. Pain, 155 (8), 1540-6 PMID: 24792624

[2] Serbic D, Pincus T. (2013). Chasing the ghosts: The impact of diagnostic labelling on self-management and pain-related guilt in chronic low back pain patients. Journal of Pain Management, 6 (1), 25-35