Low Back Pain (LBP) is the most common musculoskeletal disorder and a leading cause of disability worldwide. It is the most frequent reason for consulting general practice and has an impact on daily life and work capacity. A cornerstone in treating LBP is the provision of information to patients, and the internet is increasingly being used as a source of health information delivery. However, the effect of and satisfaction with online information have been questioned. The investigators aimed to develop and validate a multi-item instrument to measure an index score of satisfaction of online information for patients with LBP.

The conceptualization of a Patient Reported Outcome (PRO) to measure a multidimensional index score is modelled on the assumption of a causal relationship between domains of experiences with online information and patients' combined index score of satisfaction. Findings from 15 patient interviews was applied to draft the first version of the instrument. Followed by pilot testing on patients (n=20) and experts (n=7) before validating the instrument on patients (n=150). Patients were eligible for inclusion if they had their first onset of LBP for 14 days. Patients were included regardless of pain intensity. Patients were excluded if they did not have Internet access, were pregnant, did not speak Danish as their native language, or had signs of serious underlying disease.

BACKGROUND Low back pain (LBP) is highly prevalent and a frequent reason for patients to consult general practice. It is a common pain condition affecting both men and women at all ages. LBP is rarely caused by only one specific factor but is eventually caused by multiple and often unknown factors. This makes it difficult to perform a precise diagnosis based on a single cause and for most patients, the LBP is diagnosed as nonspecific with or without nerve root compression.

Patient education and information is a cornerstone in the management of LBP. Providing information to patients is considered a crucial issue as it is necessary to support self-management. However, the delivery of evidence based information by a healthcare professional is time consuming and not straight forward to deliver during the available consultation time in general practice.

The internet is a widely accessible source of medical information to patients and offer a range of information provided by a variety of different sources. It has been reported that about 50% of patients use internet search for health and medical advice, and evidence suggests that patients willingness to use this source to obtain information about their health is increasing. The advance of new technologies offer new opportunities to the delivery of patient information on private computers, tablets, and smartphones. Online information can be considered an inexpensive solution to extend the combined treatment in general practice. Therefore, future optimization of information delivery has the potential to increase the delivery of evidence-based treatment of LBP which may lead to better patient outcomes. Patient satisfaction has been suggested as an important domain when evaluating the provision of online information.

Measuring patient satisfaction is a recommended outcome measure when evaluating the effect of interventions for LBP. Furthermore, patient satisfaction may be associated with compliance to the recommended treatment. Patient satisfaction is, however, rarely applied as the primary outcome in studies of LBP. To the investigators' knowledge, there exist no instrument to evaluate specific satisfaction with information delivered online for LBP. The aim of this study is to develop and validate a new questionnaire to inform about patients' satisfaction with online information for LBP.

METHODS This is a development and validation study of a patient reported questionnaire to (1) inform about the discrepancy in satisfaction of online information for LBP between groups and (2) to evaluate changes in satisfaction over time. The conceptualization is based on a formative model, which assumes a causal relationship between different domains of satisfaction with online information and the construct of patients' combined index score of satisfaction. The first version of the instrument was based on findings from an interview study among patients consulting for LBP in Danish general practice. Data for further developing on the first version were exclusively collected for piloting and validating the instrument.

HYPOTHESIS The OPSI index scores among patients categorised as promoters will be compared to the OPSI index scores of patients categorised as non-promotors on the Net Promotor Score. Based on results from the pilot test. It is hypothesised that promotors will have an OPSI score of minimum 2.5 points more than non-promotors (0-8 Points on the Net Promotor Score).

Inclusion Criteria:

During the last year experienced LBP of any pain intensity. Regardless of present pain at inclusion.

Exclusion Criteria:

• no internet access
• pregnant women
• not able to speak/read Danish
• spinal stenosis
• serious underlying disease for low back pain (e.g. signs of fracture, cauda equina syndrome, malignancy, osteoporosis, or spondyloarthritis)

Adult patients with low back pain during the last year. Patients are recruited from social media and The SANO centre, a rehabilitation center for patients with musculoskeletal pain conditions. If recruitment will be difficult we will combine with recruitment from poster in waiting rooms at primary care physicians, physiotherapists, and/or chiropractors.