Qualification for prevention of musculoskeletal diseases. Low back pain example

Work-Related Musculoskeletal Disorders (WRMSDs) are the main cause of disability, absenteeism in the workplace, and reduced productivity in the EU [1]. Especially Low Back Pain (LBP) [2] is viewed as an increasingly severe epidemic of our times [3, 4], despite the availability of various methods of treatment.

There is a number of standardized questionnaires monitoring the progress of LBP treatment, and they are used to assess the functional condition of patients in various aspects of their professional and social life. They include Health Assessment Questionnaire – Disability Index (HAQ-DI), Oswestry Low Back Pain Disability Questionnaire (ODI), The Work Productivity and Activity Impairment Questionnaire (WPAI), and many others [5,6,7]. These questionnaires usually focus on acute low back pain, which largely prevents patients from participating in family, social, and professional life. However, they are rather lengthy and ask many complex questions, and deriving results from the answers is complicated and time-consuming. Very often the pain is persisting, has varying intensity, but never eases off completely. Nevertheless, those suffering from it continue showing up at work. In the literature, this behavior is called presenteeism and describes inefficient presence at work [8]. It has been established that prolonged presenteeism exacerbates health problems, reduces workplace efficiency, and increases absenteeism in the future [9]. It also generates some indirect costs, that is, lost profit caused by reduced productivity – in Western countries, indirect costs account for more than half of costs related to occurrence and treatment of diseases [10]. Costs of presenteeism paid by businesses are 2-3 times larger than direct costs of health care [11].

This points to a need for tools that would assess chronic pain, and this need was addressed by the project undertaken by our team, which included, among others, research presented in this paper. The goal was to validate the Functional Pain Index (FPI), a tool conceived by the authors, and compare the results with the results produced by the interview and physiotherapeutic examination conducted by a physiotherapist. The authors also attempted to determine a point range of the FPI questionnaire which would trigger qualification for a prevention program. Picture 1. shows the methodology used in calculating the FPI.

Ryc. 1.

Methodology used in calculating the FPI

For the person to be eligible for participation in the research they had to have a disability certificate. The sample group consisted of 206 workers with disability certificate (72% women vs. 28% men), employed in 16 sheltered workshops in Poland. The average age was 50.2 y.o. (median: 53 y.o.) – a detailed breakdown into specific age groups is shown in table 1. Workers who showed symptoms requiring further medical tests were excluded from the research.

The largest group, 119 persons (57.8%), performed their work while sitting at the computer. 41 persons (19.9%) performed physical work while sitting, 46 persons (22.3%) performed other physical work.

Among surveyed workers of sheltered workshops, 193 persons (93.7%) reported pain lasting over 3 months, and from among these persons as much as 176 persons (85.4%) have been experiencing pain for 12 months or longer (table 2).

The FPI used in the research was developed basing on questions conceived by the authors and was applied to assess the initial limitations in daily and professional life depending on the intensity of experienced pain. The questionnaire prepared by the authors had 15 questions inquiring about pain symptoms, its location, duration, and characteristics. The answers were used to assess whether those surveyed meet the criteria that determine whether or not a prevention program should be advised. Only 3 questions were used to calculate the FPI, and each was attributed point and percentage score. Since the FPI is a newly designed tool, point scores were estimated for various variants. After preliminary analysis 5 variants for calculation of the FPI were selected and examined throughout the project to ensure the best possible presentation of results. Choosing a smaller number of variants would oversimplify the matter, while more variants would compromise transparency. Questions used to calculate the FPI and calculation variants for the FPI are shown in picture 1. Maximal score in the questionnaire, depending on the variant, was: I – 18 points, II – 26 points, III, IV and V – 30 points each. Pain classification as per the FPI is shown in table 3.

The research was conducted between November 2015 and March 2016, and was completed in 2 stages. In the 1st stage those surveyed were asked to access an e-learning platform to fill the questionnaire on their own - the collected data were used to calculate the FPI. The questions were ciphered to ensure that their true purpose was obscure to those surveyed. In the 2nd stage an interview and physiotherapeutic examination were conducted in a separate room. Where no dangerous symptoms were observed [12], a physiotherapist qualified those surveyed for a back pain prevention program or suggested physiotherapeutic treatment. Where the cause of pain was not clear, a medical consultation for further inquiry into the cause was suggested. A physiotherapist conducting the examination was not familiar with how questionnaires were filled in the 1st stage of the research, and their assessment was independent and final.

A statistical analysis was conducted with SAS software, using the Wilcoxon test, the Chi² test, and the Spearman correlation coefficient, with statistical significance threshold set at p=0.005.

The FPI calculated basing on three variables embedded in the questionnaire showed no statistically significant difference when compared to a similar index determined basing on documentation produced by physiotherapeutic examination.

Basing on physiotherapeutic examination, prevention programs were advised to 87 persons, with the FPI for this group ranging in average from 31.9 to 36.8 points, depending on the index variant applied. 119 persons were advised physiotherapy or medical consultation, with the FPI for this group ranging on average from 51.8 to 57.5 points, depending on the index variant applied. A comparison of groups shows that they differ in a statistically significant manner (p<0.0001) in all FPI variants. Detailed results were presented in table 4.

Results show that at lower FPI scores (up to 20%) recorded in specific FPI variants, back pain prevention was suggested for 83.33%-88.89% of those surveyed in the sample group (picture 2).

Ryc. 2.

Persons qualified for prevention [%] depending on the FPI variant

For the FPI at 40%, 60% and 80%, a prevention program was advised to, respectively, 59.32%-67.21%, 27.5%-38.46% and 11.63%-13.73% of those surveyed. Where the highest FPI score (100%) was recorded, all persons were advised medical consultation and treatment. There was also a negative correlation between the FPI score and the number of persons qualified for back pain prevention (p<0.005). This correlation is presented in picture 2 and includes all FPI variants. It has been also established that there is a statistically significant correlation between a decision to advise back pain prevention and the FPI score in all its variants (p<0.001).

While determining whether a person is eligible for a prevention program one needs to decide whether such prevention is advisable as well as assess the functional condition of a patient in order to ascertain whether they should seek medical consultation and treatment [13]. When encountering symptoms that may have their source in the spine one may consider consulting with a neurosurgeon [14]. Currently Poland has no standardized and nationwide back pain prevention programs, and Supreme Audit Office has never produced any reports shedding light on prevention of musculoskeletal problems. Systemic prevention is practically non-existent in the guaranteed healthcare services system as it exists in Poland today.

Back pain prevention comes into question when pain has been experienced recently or has been recurring, radiating to a lower extremity, or causing absenteeism [14]. In order to assess risk factors which, when established, should result in specialist treatment, one should conduct a detailed examination of pain intensity and complete a check for possible „red flags.” According to the latest research, LBP is associated with 41 risk factors, 51 concomitants and 39 parallel diseases, some of which are difficult to tell apart [15, 16]. In the process of qualifying for back pain prevention one may use standardized questionnaires typically used to assess progress in treatment [5,6,7]. They provide, however, too much data difficult to interpret using only algorithms, and so usually one resorts to various forms of a questionnaire which, after initial analysis, allows to single out patients suffering from recurring back pain who could benefit from prevention programs [14]. At the same time, the questionnaire is designed in such a way as to separate patients who potentially need a detailed physiotherapeutic examination and, possibly, treatment.

The questionnaire and the FPI developed by our team allow to assess how advanced the pain is. The results described above show a high consistency between answers given in the questionnaire and answers given to a physiotherapist during the interview, proving the questionnaire’s reliability. Regardless of the questionnaire variant, the general correlation does not change between the FPI score and a decision whether back pain prevention should be advised or not. One may conclude that the choice of questions from which the FPI is derived was correct and consistent with criteria applied by a physiotherapist exercising their individual judgment.

Considering the results in relation to various FPI variants (1-5), one may also note that variants 2 and 4 are quite closely matched. Furthermore, compared to other variants, variant 3 is characterised by a low-point score in the entire middle range (20-80%). Variant 1 produces overstate results in 0-40% range, while variant 5 produces higher results in 40-80% range. Considering in addition that the results are linear, we conclude that the most reliable FPI variants are variants 2 and 4.

It has been observed that a critical point while qualifying for back pain prevention or physiotherapy/consultation occurs in the FPI score ranging from 40% to 60%. One may therefore tentatively assume that all persons with results within 0-40% range of the FPI (minimal or moderate pain) can be safely qualified for prevention programs. For the FPI ranging from 40% to 60% (persisting pain) one would suggest an additional assessment with follow-up “red flag” questions asked in the e-qualification system [12]. Finally, persons with the FPI above 60% (persisting or extreme pain) should be examined by a physiotherapist before being advised back pain prevention or treatment. It should be noted, however, that a simulation exercise should be conducted to verify these observations.

The FPI enables assessment of the initial condition of patients complaining about persisting back pain. It can be probably also applied to monitor progress in back pain treatment, and may be useful in system-wide qualification as a complementary tool for software-enabled qualification for back pain prevention, with one of its core advantages being simplicity (3 questions) – as opposed to other questionnaires available today which are characterized by high complexity.

• High consistency between the FPI based on the questionnaire and physiotherapeutic examination proves that the questionnaire is highly reliable.

• Correlation between a physiotherapist decision to qualify for back pain prevention and the result produced by the FPI questionnaire shows that it can serve as a good alternative for qualifying patients for prevention programs, with questionnaire-based qualification for a prevention program triggered in 0-40% range of the FPI.

• As a new assessment tool, the FPI questionnaire needs to be refined by determining its most optimal variant, followed by a relevant simulation exercise based solely on this choice.