Epidemiological, humanistic, and economic burden of illness of lower limb spasticity in adults: a systematic review

Abstract

Background

The purpose of this study was to investigate the epidemiological, humanistic, and economic burden of illness associated with adult lower limb spasticity (LLS) and its complications.

Methods

A systematic search of MEDLINE and EMBASE identified 23 studies published between January 2002 and October 2012 that assessed the epidemiology, impact, and resource use associated with LLS. A hand-search of four neurology conferences identified abstracts published between 2010 and 2012.

Results

LLS was found to occur in one third of adults after stroke, half to two thirds with multiple sclerosis, and three quarters with cerebral palsy. LLS limits mobility and reduces quality of life. No clear association was found between LLS and occurrence of pain, development of contractures, or risk of falls.

Conclusion

The evidence on the burden of LLS and its complications is surprisingly limited given the condition’s high prevalence among adults with common disorders, such as stroke. Further research is needed to clarify the impact of LLS, including the likelihood of thrombosis in spastic lower limbs. The dearth of high-quality evidence for LLS suggests a lack of awareness of, and interest in, the problem, and therefore, the unmet need among patients and their carers.

Keywords:

• muscle spasticity
• cost of illness
• complications
• quality of life

Supplementary materials

Search strategy

Database searches

Gray literature search

We searched the gray literature (material that can be referenced but is not published in peer-reviewed MEDLINE-indexed or EMBASE-indexed medical journals) for any information pertaining to epidemiologic, quality of life, and economic outcomes of the burden of LLS. We manually searched the following websites for articles relevant to LLS, using the same inclusion criteria as for the database searches:

• World Federation for Neurorehabilitation (http://wfnr.co.uk)

• World Stroke Congress (http://www1.kenes.com/wsc)

• World Federation of Neurology (http://www.wfneurology.org)

• American Neurological Association/Association of British Neurologists (http://www.aneuroa.org)

Inclusion and exclusion criteria

Inclusion criteria

Patient population

• Patients older than 18 years of age with LLS, that could have resulted from any of the following underlying diseases:

  • ○ Stroke

  • ○ Multiple sclerosis

  • ○ Traumatic brain injury

  • ○ Cerebral palsy

  • ○ Others, for example, Parkinson’s disease

• Studies reporting follow-up from childhood to adulthood

• Studies with more than 50% adult populations

Outcomes

• Epidemiologic outcomes

  • ○ Prevalence and incidence of LLS due to different underlying pathologies, as listed above under population

  • ○ Trends of LLS over time

  • ○ Outcomes and prognosis of LLS

  • ○ Health and social problems associated with LLS

  • ○ Comorbidities associated with LLS

  • ○ Treatment patterns with botulinum toxin or other interventions in adults with LLS

• Humanistic/quality of life outcomes

  • ○ Utilities associated with LLS

  • ○ Quality of life outcomes with LLS

  • ○ Patient-reported outcomes

  • ○ Patient satisfaction with treatment/care for LLS

  • ○ Burden on carers of patients with LLS

  • ○ Quality of life associated with efficacy/effectiveness of treatment for LLS

  • ○ Access to care

  • ○ Unmet needs

• Economic outcomes

  • ○ Direct costs of LLS (health and social care)

  • ○ Indirect costs of LLS (eg, productivity, employment for patients and carers)

  • ○ Resource use by patients with LLS and carers, including costs and resource use associated with treatments for LLS (pharmacological or non-pharmacological)

  • ○ Burden on society from LLS

Year of publication

• Studies published in the last 10 years (2002–2012)

Languages

• Only publications in English were considered

Study design

• Primary research including cohort studies, case-control studies, cross-sectional studies, case series, and randomized controlled trials (if available), and database studies

Exclusion criteria

Patient population

• Studies investigating patients without LLS

• Studies on adolescents and children younger than 18 years of age with LLS

Outcomes

• Articles without relevant data on any of the outcomes of interest

• Studies on genetic profiling

• Prevalence studies with fewer than ten participants

• Articles investigating the efficacy and/or effectiveness of botulinum toxin or any other investigation in the treatment of LLS

• Studies investigating the biomechanical factors associated with spasticity (eg, electromyogram findings, joint angle, foot position, muscle blood flow)

• Studies assessing the validity of instruments used to measure spasticity

Study design

• Letters to the editor

• Narrative reviews

• Editorials

• Expert opinions

• Case studies

Articles were not excluded based on the geographic location. Systematic review articles published in the past four years (October 2008–October 2012) and meeting abstracts from the last two years or last two conference meetings were also included.

Abbreviation: LLS, lower limb spasticity.

Table S1 Search string for MEDLINE-indexed publications

Table S2 Search string for EMBASE-indexed publications

Acknowledgments

The authors would like to acknowledge the following contributors to this article: Ike Iheanacho, who provided editorial input, and Louise Lombard, Amy McDonough, and Erica Zaiser, who contributed to data collection and analysis.

Disclosure

AM and SA are both employed by Evidera. HK and JD are employees of Ipsen. The authors report no other conflicts of interest in this work. Funding of this literature review was provided by Ipsen Pharma SAS.