By Michael Broder, PhD
Reviewed by Christopher Gharibo, MD, Medical Director of Pain Medicine, NYU Langone Medical Center Hospital for Joint Diseases, New York, NY
- A recent study among people with fibromyalgia found that poorer physical function, overall disease impact, and disease severity were associated with a worse physical component of HRQOL.
- By contrast, physical activity, eating, and strategies for coping with pain were associated with a better physical component of HRQOL.
- A higher overall disease-impact score was associated with a negative impact on the mental component of HRQOL, as were higher levels of depression and anxiety.
People with fibromyalgia have lower health-related quality of life (HRQOL) than those with other chronic conditions or the general population. “Fibromyalgia must be understood as a complex dimensional disorder beyond being a chronic widespread pain condition,” said Víctor Segura-Jiménez, PhD, assistant professor in the Faculty of Education Sciences at the Department of Physical Education, University of Cádiz. “The large quantity of symptoms that patients suffer entails an enormous impact on the management of daily simple tasks, such as bathing, doing the bed, or simply walking, which consequently affects patients’ HRQOL,” Dr. Segura-Jiménez added.
While a range of factors impact HRQOL, the role of HRQOL as an outcome of fibromyalgia has not been widely studied. In a recent study, Lee and colleagues assessed the relationships between physical function, social factors, and psychological factors among people with fibromyalgia and evaluated the impact of these variables on HRQOL.1
This study is the first to explore the role of HRQOL among people with fibromyalgia using structural equation modeling (SEM), a method that brings together a number of statistical techniques including path analysis, confirmatory factor analysis, and regression analysis to determine relationships among independent variables. This method includes latent variables as well as observed ones.1
Latent variable are those that are important to the model but for which there are no observed data.2 For example, sharp pain may be an important variable for modeling HRQOL in people with fibromyalgia, but there may be no objective measure of sharp pain that can be observed, so sharp pain becomes a latent variable, and participant self reports of perceived sharp pain serves as an observed variable used to measure the latent variable.2 A SEM allows the researcher to estimate the relationship between various observed indicators of sharp pain and the latent variable of sharp pain itself, as well as to determine which observed indicator is most closely related to the latent variable. A latent variable SEM lets researchers study how latent variables relate to each other as well as to study how latent variables relate to observed variables. In this way, the study can analyze relationships among relevant variables free from the confounding effects of measurement error.2
Lee and colleagues assessed HRQOL using the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). They assessed physical dysfunction via the Fibromyalgia Impact Questionnaire (FIQ).1 Both of these tools have shown value in assessing HRQOL in people with fibromyalgia.3 They measured social and psychological status using the Beck Depression Inventory (BDI), the State-Trait Anxiety Inventory (STAI), and the Arthritis Self-Efficacy Scale (ASES), all of which are widely used in studies of patients with chronic pain and have been used in other recent studies of fibromyalgia.1,3-7 They assessed the perceived adequacy of social support from family using the Korean social support questionnaire (KSSQ).1,7 For the statistical analysis, they assessed the impact of physical, psychological, and social influences on HRQOL using Analysis of Moment Structure (AMOS; ver. 16.0), a statistical software program used for causal modeling.1 The study included 336 participants. Of these, some 90% were women with an average age about 48 (plus or minus 11 years).1
This study demonstrates how physical, social, and psychological variables are related to HRQOL in people with fibromyalgia.1 The study found that FIQ and self efficacy had direct impacts on the physical component of HRQOL.1 In particular, a higher FIQ score—indicating poorer physical function, overall impact of the disease, and disease severity—was associated with a worse physical component of HRQOL. By contrast, higher self efficacy—which includes physical activity, eating, and strategies for coping with pain—was associated with a better physical component of HRQOL. The study also found that FIQ, BDI, and STAI had a direct impact on the mental component of HRQOL.1 Specifically, a higher FIQ score was associated with a negative impact on the mental component of HRQOL, as were higher levels of depression and anxiety.1
- Lee JW, Lee KE, Park DJ, et al. Determinants of quality of life in patients with fibromyalgia: a structural equation modeling approach. PLoS One. 2017;12:e0171186. doi: 10.1371/journal.pone.0171186. eCollection 2017.
- Bollen KA, Noble MD. Structural equation models and the quantification of behavior. Proc Natl Acad Sci U S A. 2011;108 Suppl 3:15639-15646. doi: 10.1073/pnas.1010661108. Epub 2011 Jul 5.
- Assumpção A, Pagano T, Matsutani LA, et al. Quality of life and discriminating power of two questionnaires in fibromyalgia patients: Fibromyalgia Impact Questionnaire and Medical Outcomes Study 36-Item Short-Form Health Survey. Rev Bras Fisioter. 2010;14:284-289. Epub 2010 Jul 23.
- Comeche Moreno MI, Ortega Pardo J, Rodríguez Muñoz Mde L, et al. Estructura y adecuación del Inventario de Depresión de Beck en pacientes con fibromyalgia. Psicothema. 2012;24:668-673.
- López-Pousa S, Bassets Pagès G, Monserrat-Vila S, et al. Sense of well-being in patients with fibromyalgia: aerobic exercise program in a mature forest-a pilot study. Evid Based Complement Alternat Med. 2015;2015:614783. doi: 10.1155/2015/614783. Epub 2015 Oct 18.
- Menzies V, Taylor AG, Bourguignon C. Effects of guided imagery on outcomes of pain, functional status, and self-efficacy in persons diagnosed with fibromyalgia. J Altern Complement Med. 2006;12:23-30.Non-Pharmacologic Management Strategies for Fibromyalgia
By Erin M. Burns, PhD, MSPH
Reviewed by David Fernandez, MD, Assistant Attending, Adult Rheumatology, Hospital for Special Surgery, New York, NY