The Acute Care of Stroke Patients in German Stroke Units—an Analysis of DRG Data From 2021 and 2022

Treating stroke patients in a stroke unit is recommended in guidelines and has developed into a worldwide standard (1). The present article investigates the shares of healthcare provided by different stroke units (with or without specialist neurology department; regional, supraregional, or telestroke units; categorization by emergency level) in Germany.

Methods

In Germany, treatment in a stroke unit is coded by hospitals as complex treatment (OPS [Operationen- und Prozeduren-Schlüssel [German procedure classification]; www.dimdi.de] 8–981.- or 8–98b.-). The OPS codes allow for drawing valid conclusions about the structure of the billing institution. The stroke units were categorized according to their complex treatment procedure[s] into:

• OPS 8–981: stroke unit with specialist neurology department on site

  • Regional stroke unit (OPS: 8–981.2-): without continuing option for carrying out thrombectomies and intracranial interventions

  • Supraregional stroke unit (OPS: 8–981.3-): with option to carry out thrombectomies and intracranial interventions

• OPS 8–98b: stroke unit offering another complex neurology treatment

  • Without teleconsultation service (8–98b.2-)

  • With teleconsultation service (8–98b.3-)

Recanalization treatments were evaluated by means of the main diagnosis I63 in combination with

• OPS 8–020.8 (systemic thrombolysis; IVT),

• OPS 8–836.80 (thrombectomy; MTE)

The analysis is based on DRG [diagnosis related groups] data (InEK data browser for the reporting years 2021 and 2022; www.g-drg.de/) and the quality reports (www.g-ba.de) for the reporting year 2021. Sites with less than 10 cases were excluded from the concluding evaluation.

The categorization by level in the system of emergency structures according to § 136c para 4, 5^th book of the Social Code Germany was done at the level of the site numbers (2).

Results

The main diagnosis stroke (ICD: G45, I60, I61, I63, I64) was coded in 335 905 cases in 2021. In 239 239 of these cases (71.22%) complex treatment for stroke (OPS: 8–981 or 8–98b) was administered in a stroke unit. In another 5.08% of cases, complex treatment regarding intensive care medicine was coded, but not complex treatment for stroke.

In 2021 and 2022, complex treatment for stroke (Table) was given in almost 90% of cases in an institution where a specialist neurology department on the site of the stroke unit is a required structural characteristic. Just over half of these patients received care in a supraregional stroke unit with neurology department. The proportion of those who received care in a telestroke unit rose from 4.98% in 2021 to 6.52% in 2022. Complex treatment in a stroke unit was provided by n=475 hospitals (>10 cases per year (Table). Some 92% of stroke patients were treated in these institutions. Of these, 77% underwent complex treatment; no complex treatment was given to the remaining stroke patients (23%) (reasons included that palliate care was the primary objective or that stroke had not been suspected initially). The hospitals that regularly administered complex treatment were allocated to the following levels according to the system of levels of emergency structures: level I (basic)—165 institutions (34.7%), level II (extended)—133 institutions (282.0%), level III (comprehensive)—157 institutions (33.1%); no allocation in 20 institutions (4.2%). Institutions of levels I, II, and III carried out a median of n=301, n=450, and n=712 complex stroke procedures, respectively. The vast majority (93.3% in 2021) of recanalization treatments (intravenous thrombolysis [IVT], mechanical thrombectomy [VTE]) were carried out in a stroke unit with neurology department. Mechanical thrombectomies were largely done in institutions with a supraregional stroke unit (88%).

Table. Case numbers in different stroke units.

		SU (all)	SU-N		aSU
		OPS: 8–981 + 8–98b	OPS: 8–981		OPS: 8–98b
Number of institutions (%)		475 (100 %)	334 (70.3 %)		141 (29.7 %)
Case numbers of complex treatments per SU median (lower and upper quartile)		470 (233; 760)	622 (420; 845)		158 (76; 266)
Case numbers of complex treatments per SU type		SU (all) OPS: 8–981 + 8–98b	rSU-N 8–981.2	srSU-N 8–981.3	aSU (without T) 8–98b.2	aSU (with T) 8–98b.3
Year 2021	All strokes (G45, I60, 61, 63, 64)	239 239	102 581	111 067	13 678	11 913
	Proportion of total	100.00 %	42.88 %	46.43 %	5.72 %	4.98 %
Year 2022	All strokes (G45, I60, 61, 63, 64)	232 432	98 785	108 477	10 013	15 157
	Proportion of total	100.00 %	42.50 %	46.67 %	4.31 %	6.52 %

SU-N (OPS 8–981): regional or supraregional SU with specialist neurology department; rSU-N or srSU

NaSU OPS 8–98b): SU with different complex treatment (with and without teleconsultations)

SU, stroke unit; SU-N, stroke unit with specialist neurology department

Discussion

Most complex stroke treatments (90%) were carried out in stroke units in institutions that code OPS 8–981; the requirement is a neurology department on site. In the remaining 10% of cases, OPS 8–98b was coded, which does not require a neurology department. Treatment was given mostly under the direction of internal medicine, and the neurological expertise has to be included in order to bill for complex treatment (for example, by teleconsultation).

Currently 348 certified stroke units are in operation in Germany (3). According to the data presented here, 475 institutions participated in stroke care and billed for complex treatments (>10 cases) in a stroke unit. Of these, 400 institutions reached the minimum case numbers for certification (n=250, for telestroke unit 200). This means that almost 90% of stroke units with sufficiently high case numbers are certified in Germany, which is a high degree of certification. In the context of the planned hospital reform (4), considerations for restructuring stroke care are under discussion. The basis for this consists of data—among others—that have found an association between a better patient outcome and treatment in stroke units when applying certain minimum criteria (among others, case numbers>250, complex treatments >125/year) (4, 5). On the basis of the present analysis it can be estimated that if a comparable minimum case number were used, about 75 out of 475 institutions (see above) would not meet the criteria.

Comparison with the allocated emergency levels shows that even institutions with the currently lowest emergency level I (basic emergency care) currently participate in stroke care (some 23.5% of complex treatments). It would therefore be impossible to focus stroke care merely on emergency levels II and III without substantially restructuring the care landscape.

In sum, the data confirm that most stroke patients in Germany are now being treated in stroke units under the direction of neurology. To this end, networks with institutions of different care levels (regional, supraregional/national, and telestroke units have been established). Sites with very small case numbers contribute little to acute stroke treatment and are probably not needed; the specific regional care need will have to be considered at the individual case level.