Low back pain (LBP) is the condition producing the greatest number of years a patient may live with a disability. An important question in pain research is to investigate the transition from an acute state of pain (a very recent episode), to a persistent state where living with pain can last for more than three months and in some cases, even many years. However, how does the initial definition of acute LBP can impact the study results?
goal
Research studies may use different definitions of acute LBP, some considering or not a pain-free period before the onset of the current pain episode and others will consider the pain is acute even though pain is present for more than three months if pain frequency was low. In this study, the research team looked at the impact of different definitions of acute LBP on the number of participants meeting the different definition of acute LBP as well as their clinical profile.
methodology
The self-reported data was analyzed from a total of 1 264 participants enrolled in the Quebec Low Back Pain Study. Participants were asked to report demographic information such as age, sex at birth, height and weight and smoking status among many others. Details about the pain characteristics and quality of life (duration, intensity, interference with daily activities, etc.) were also collected. Three different definitions of acute LBP were used : nonchronic LBP, acute LBP and new episode of acute LBP.
main findings
25.9 % of participants met all three definitions and 32.9 % met the definitions of acute or new episode of LBP as well as the NIH definition of chronic LBP. More participants met the criteria for the nonchronic LBP definition, than the other two definitions. The pain interfered less with the daily activities for the participants corresponding to the nonchronic LBP definition. These participants presented a better clinical profile, for example better physical function than the ones meeting the acute and new episode of LBP.
take home message
The choice of a definition influences the clinical profile of the acute LBP group and may confound the identification of important factors when studying the transition from recent to persistent LBP.
