The Incidence and Outpatient Medical Care of Patients with Post-Stroke Spasticity

Almost one third of stroke survivors develop post-stroke spasticity [PSS] which is one of the major causes of a severely restricted quality of life. The German guideline on the treatment of spastic syndrome (1) recommends a multidisciplinary approach for PSS management, comprising physical therapy as a basic treatment option and, where necessary, supplementary antispasticity medication. Regular botulinum neurotoxin type A (BoNT-A) injections are generally regarded as first-line pharmacological therapy. Oral antispasticity drugs should only be prescribed restrictively due to their systemic side effects. The present study examines the outpatient medical care of German patients with PSS, taking into account treatment with physiotherapy/occupational therapy and antispasticity/analgesic medication, and assesses compliance with German guideline recommendations using a secondary data analysis of routine health insurance data.

Table 2. Reasons for non-compliance with the PSS guideline criteria during the follow-up observation period of two years after PSS diagnosis, taking scenario II as an example.

Total number of analyzed PSS patients, n (%)	7947	(100)
Number of PSS patients
–  with guideline-based treatment – without guideline-based treatment	2937 5010	(37.0) (63.0)
Reasons for non-compliance with the PSS guideline criteria
– no regular physiotherapy – prescription of oral antispasticity drugs without BoNT-A treatment – BoNT-A, but without regular physiotherapy – treatment with physiotherapy, BoNT-A, and oral antispasticity drugs; the order of their application, however, does not correspond to the guideline recommendations	4459 510 8 40	(56.1) (6.4) (0.1) (0.5)

BoNT-A, botulinum toxin type A; PSS, post-stroke spasticity

Methods

The study is based on a sample drawn from the InGef research database [Institute for Applied Health Research Berlin] for the insurance years 2015–2019 and containing anonymized longitudinal claims data (including inpatient and outpatient treatments) of around four million people covered under the German statutory health insurance scheme. The sampling strategy is described elsewhere (2) and selected a representative data set of the German population with respect to morbidity, mortality, and drug usage. The patient-level data were fully anonymized, so ethical approval was not required (2). Data from rehabilitation clinics were not included. First of all, PSS incidence was estimated using a cross-sectional research design. Then, in a longitudinal cohort design, outpatient medical care was descriptively analyzed for an individual patient follow-up observation period of two years after PSS diagnosis. Patients with a first stroke and no history of spasticity were identified by an inpatient, stroke-specific ICD-10-GM diagnosis code (I60, I61, I63 and I64). PSS was assumed, amongst other things, if an outpatient or inpatient diagnosis of spastic or non-specific paralysis (G81.1, G82.1, G82.4, G81.9) had been made within one year of the diagnosis of stroke.

Guideline compliance was estimated using three different scenarios which differed in their prescription frequency and specificity for physiotherapy as the fundamental treatment option. In scenario I, at least one, in scenario II regular (during at least four to eight quarters of the follow-up observation period), and in scenario III regular, PSS-specific, prescriptions for physiotherapy with the explicit indication stroke or spasticity were regarded as guideline-compliant. BoNT-A treatment initiated together with, or after, physiotherapy was guideline-compliant in all three scenarios. Treatment with oral antispasticity drugs started together with, or after, BoNT-A treatment was also guideline-compliant. The prescription of oral antispasticity drugs without initial BoNT-A treatment was regarded as non-guideline compliant—without taking medical exceptions into account.

Results

Between the years 2015 and 2019, annual PSS incidence ranged from 295.4 (95% confidence interval: [286.4; 304.6]) to 317.8 [308.5; 327.2] per 1000 patients with stroke. It was around 9% higher in men than in women and approximately 14% higher in those affected aged 55 years or older than in younger patients.

The inclusion criteria for the analysis of outpatient PSS care was fulfilled by 7947 patients (median age 74 years, interquartile range 63–80, 48.1% female) who were then followed-up for two years. PSS was diagnosed in 4734 (59.6%) patients within three months of developing stroke. The diagnosis of PSS was primarily made in the outpatient setting by specialists in general medicine (3749 patients, 47.2%) or neurologists (859 patients, 10.8%) and in hospital (2246 patients, 28.3%). During the follow-up observation period, 3488 (43.9%) patients with PSS received physiotherapy regularly, yet only 1985 (25.0%) had a PSS-specific prescription. Eight hundred and fifteen (10.3%) received at least one prescription for oral antispasticity drugs and 80 (1.0 %) for BoNT-A (table 1). Guideline compliance was estimated for 5287 (66.5%) patients in scenario I, for 2937 (37.0%) patients in scenario II, and for 1738 (21.9%) in scenario III, and did not differ with respect to age, place of residence (urban/rural) or stroke subtype, being slightly higher in women than in men. Compare Table 2 for reasons of non-compliance with PSS guideline criteria, taking scenario II as an example.

Table 1. Use of outpatient physiotherapy/occupational therapy, antispasticity drugs and analgesics over a 2-year-old follow-up observation period after the diagnosis of.

PSS patients, n (%)	7947 (100)
	n (%)	Prescriptions per patient median (IQR)	Treatment units per patient median (IQR)
Physiotherapy
–  at least one prescription – regular prescriptions – regular PSS-specific prescriptions	6021 (75.8) 3488 (43.9) 1985 (25.0)	7 (2–12) 11 (8–15) 10 (7–14)	51 (18–110) 100 (66–140) 92 (66–132)
Occupational therapy
– at least one prescription – regular prescriptions – regular PSS-specific prescriptions	3426 (43.1) 1978 (24.9) 1302 (16.4)	6 (2–10) 10 (7–10) 9 (6–13)	54 (21–101) 91 (66–131) 87 (61–124)
	n (%)	Prescriptions per patient median (IQR)	Prescribed DDD per patient median (IQR)
Antispasticity drugs and analgesics
–  at least one prescription for oral antispasticity drugs – at least one prescription for BoNT-A – regular prescriptions for analgesics	815 (10.3) 80 (1) 708 (8.9)	3 (1–11) 3 (1–5) 23 (16–31)	92 (20–400) not defined 317 (236–454)

Treatment unit data were retrieved from billing information submitted by therapists.

Regular pain medication was regarded to be the prescription of more than 180 DDDs during the follow-up observation period.

BoNT-A, botulinum toxin type A; DDD, defined daily dose; IQR, interquartile range; PSS, post-stroke spasticity

Discussion and recommendations

In our study, almost one third of the patients with stroke were diagnosed with PSS – mainly within the first three months of suffering a stroke. This is consistent with existing literature (3–5) and demonstrates an appropriate sampling strategy. A certain degree of misclassification is possible, however, due to the use of ICD-10 codes for patient identification. The minority of analyzed patients with PSS were treated in a guideline-compliant manner. It is worth noting here that only 1% of patients with PSS received BoNT-A, yet 10% received oral antispasticity drugs. Possible reasons for the lack of guideline compliance could lie in budgeting for physical therapy, inadequate remuneration for BoNT-A funding application resulting in the limited number of BoNT-A users, poor knowledge of the treatment guidelines, or patient preference. In order to improve guideline compliance, BoNT-A treatment should also be clearly expanded beyond otherwise regular PSS-specific physical therapy. We would suggest, as a first step, that all patients with PSS who are currently being treated exclusively with oral antispasticity drugs are assessed for possible BoNT-A treatment, since these patients in particular may be assumed to be suffering from painful and/or disabling spasticity. Finally, the special role of specialists in general medicine in the care of patients with PSS should be highlighted as well as their referral to experienced spasticity therapists, since in Germany they are the ones who make the diagnosis of PSS in the first place.