Die Tonsillektomie (TE) zielt darauf ab, die Gaumenmandeln als Ursache von rezidivierenden akuten Tonsillitiden zu entfernen, wenn diese konservativen Maßnahmen nicht zugänglich sind. Konsentierte Leitlinienempfehlungen hierzu wurden in Deutschland im Jahr 2015 publiziert. Die vorliegende Studie zielte darauf ab, dem Effekt dieser Leitlinie auf die Indikationsstellung der TE unter Nutzung von individuellen Patientendaten nachzugehen. Anonymisierte Abrechnungsdaten der Allgemeinen Ortskrankenkassen aus stationärer und ambulanter Behandlung sowie Arzneiverordnungsdaten der Jahre 2012–2018 wurden personenbezogen zusammengeführt und ausgewertet. Über die Operationscodierung wurden alle Tonsillektomiefälle erfasst, die wegen einer „chronischen Tonsillitis“ ausgeführt worden waren. Die ambulante Vorbehandlung wegen Halsschmerzepisoden wurde mittels der relevanten ICD-10-Diagnoseschlüssel und die Arzneiverordnungen anhand des anatomisch-therapeutisch-chemischen Systems identifiziert. Zur Auswertung waren 109.895 Krankenhausfälle geeignet, die einen Fallzahlrückgang von 50,3 % innerhalb des Beobachtungszeitraums ergab. Der kontinuierliche Rückgang erhielt einen Akzent nach 2015. Besonders stark waren davon die unter 10-Jährigen betroffen (−65,7 %). Bei etwa der Hälfte aller Tonsillektomierten fanden sich in keinem oder nur einem Quartal ambulante antibiotische Vorbehandlungen. Auf die Fallzahlentwicklung und gängige Praxis bei der Behandlung von Halsschmerzen ließ sich nur ein sehr limitierter Leitlinieneffekt nachweisen. Antibiotikaverordnungen spielen bei der Indikationsstellung der TE als Therapie von Halsschmerzen eine untergeordnete Rolle.

BACKGROUND:Many studies showed that hospital and surgeon volume have a significant influence on the complication rates of thyroid surgery. The present study investigates whether this relationship applies in subtotal as well as total lobe resections. Furthermore, it is still unclear which threshold for the hospital-related case volume can be determined, above which the risk of complications lies below the current national average.MATERIAL AND METHODS:The study was based on nationwide routine data for persons insured with the Local General Sickness Fund (AOK) who had undergone thyroid surgery in 2014-2016. Permanent vocal cord palsy, bleeding and wound infection needing revision were recorded using indicators. The effect of the case volume on the indicators and the case number threshold was determined using logistic regression.RESULTS:Permanent vocal cord palsy was observed in 1.3% and bleeding or wound infections needing revision in 1.6% and 0.3% of the cases. Compared to hospitals with >450 surgeries per year, the risk of permanent vocal cord palsy in hospitals with fewer than 201, 101 and 51 surgeries was significantly increased (OR [95% CI]: 1.5 [1.1-2.1]; 1.5 [1.1-2.1]; 1.8 [1.3-2.5]). The threshold needed to achieve a risk for permanent vocal cord palsy below the national average (1.3%) was 265 thyroid surgeries per year (95% CI: 110-420). For bleeding or wound infection in need of revision, no association between volume and outcome was found.CONCLUSION:The present study showed that the risk of postoperative permanent vocal cord palsy decreased with increasing case volume. The broad confidence interval of the threshold makes clear case volume recommendation difficult. In order that the risk for a postoperative permanent vocal cord palsy is not likely above the national average, the annual case volume should reach 110 thyroid interventions.

Purpose: COVID 19 pandemic had multiple influences on the social, industrial and medical situation in all affected countries. Measures of obligatory medical confinement were suspensions of scheduled non-emergent surgical procedures and outpatients clinics as well as overall access restrictions to hospitals and medical practices. The aim of this retrospective study was to assess if the obligatory confinement (lockdown) had an effect on the number of appendectomies (during and after the period of lockdown). Methods: This retrospective study was based on anonymized nationwide administrative claims data of the German Local General Sickness Fund (AOK). Patients admitted for disease of the appendix (ICD-10: K35-K38) or abdominal and pelvic pain (ICD-10: R10) who undergone an appendectomy (OPS: 5-470) were included. The study period included six weeks of German lockdown (16.03.-26.04.2020) as well as six weeks before (03.02.-15.03.2020) and after (27.04.-07.06.2020). These periods were compared to the respective in 2019. Results: Overall number of appendectomies was significantly reduced during the lockdown time in 2020 compared to 2019. This decrease affects only appendectomies due to acute simple and non-acute appendicitis. Numbers for appendectomies in acute complex appendicitis remained unchanged. Female patients and in the age group 1-18 years showed the strongest decrease in number of cases. Conclusion: The lockdown in Germany resulted in a decreased number of appendectomies. This affected mainly appendectomies in simple acute and non-acute appendicitis, but not complicated acute appendicitis. The study gives no evidence, that the confinement measures resulted in a deterioration of medical care for appendicitis.

In dieser Studie wurden die Häufigkeiten postoperativer Logopädieverordnungen bei Schilddrüsenoperationen anhand deutschlandweiter Routinedaten bestimmt, in den Kontext von Stimmbandlähmungen gesetzt und Volume-Outcome-Zusammenhänge untersucht.

Collecting clinical data is viewed as the gold standard for assessing health-care quality. However, considerable investment is needed if the quality of care is to be recorded over a long period of time. Accordingly, the question arises as to whether routine administrative data may be used for quality assurance purposes if certain methodological standards are followed. This present study now compares the outcomes of inguinal hernia repair from the Herniamed Hernia Registry with routine data from Germany’s largest sickness fund, the Local General Sickness Fund “AOK”. Included in the study were the hospital inpatient cases for the years 2011–2013 with inguinal hernia surgical repair whose data had been prospectively entered into the voluntary Herniamed Hernia Registry by 318 participating hospitals. These collectives were then compared, on the basis of the routine administrative data available, with patients from the AOK sickness fund who had been operated on during the same time period. The outcome criteria selected were the perioperative complication rates within 30 days as well as the recurrence rate and the pain rate requiring treatment at 1-year follow-up. The data records examined comprised 64,748 cases from the Herniamed Registry and 130,121 AOK cases. Since in the Herniamed collective, the proportion of bilateral procedures was significantly higher, only the collectives of elective primary unilateral inguinal hernias in men (Herniamed n = 37,667; AOK n = 78,973) were compared. The most pronounced difference between these two collectives was in the proportion of laparo-endoscopic procedures (Herniamed 61.3% vs AOK 49.0%; p < 0.001). Accordingly, the Herniamed collective was found to have a significantly lower postoperative surgical complication rate (Herniamed 1.5% vs AOK 2.6%; p < 0.001) and surgical site infection (SSI) rate (Herniamed 0.3% vs AOK 0.6%; p < 0.001) within 30 days after the operation. On the other hand, the pain rates requiring treatment in the Herniamed collective were somewhat higher (Herniamed 3.0% vs AOK 2.6%; p < 0.001). No difference was found in the recurrence rate at 1-year follow-up (Herniamed 1.0% vs AOK 0.9%; ns). Subject to critical evaluation of the limitations of data acquisition in this study, it does appear possible to use the routine administrative data from the AOK Sickness Fund for assessment of the quality of inguinal hernia surgery in Germany. Voluntary participation in the Herniamed Registry appears to be characterized by the fact that the participating hospitals conduct a higher proportion of laparo-endoscopic inguinal hernia repair. That could possibly explain the differences in outcome. However, in large patient collectives, statistical significance should not always be equated with clinical relevance. Univariate analysis does not take account of differences in the hernia findings, risk factors or operative details. Further efforts should be employed in future to improve the accuracy and granularity of routine administrative data for assessing the quality of care and to decrease the cost of gathering such data.

Introduction Inguinal hernias are repaired using either open or minimally invasive surgical techniques. For both types of surgery it has been demonstrated that a higher annual surgeon volume is associated with a lower risk of recurrence. This present study investigated the volume-outcome implications for recurrence operations, surgical complications, rate of chronic pain requiring treatment, and 30-day mortality based on the hospital volume. Materials and methods The data basis used was the routine data collected throughout the Federal Republic of Germany for persons insured by the Local General Sickness Fund “AOK” who had undergone inpatient inguinal hernia repair between 2013 and 2015. Complications were recorded by means of indicators. Hospitals were divided into five groups on the basis of the annual caseload volume: 1–50, 51–75, 76–100, 101–125, and ≥ 126 inguinal hernia repairs per year. The effect of the hospital volume on the indicators was assessed using multiple logistic regression. Results 133,449 inguinal hernia repairs were included. The incidence for recurrence operations was 0.95%, for surgical complications 4.22%, for chronic pain requiring treatment 2.87%, and for the 30-day mortality 0.28%. Low volume hospitals (1–50 and 51–75 inguinal hernia repairs per year) showed a significantly increased recurrence risk compared to high volume hospitals with ≥ 126 inguinal hernia repairs per year (odds ratio: 1.53 and 1.24). No significant correlations were found for the other results. Conclusions The study gives a detailed picture of hospital care for inguinal hernia repair in Germany. Furthermore, it was noted that the risk of hernia recurrence decreases in line with a rising caseload of the treating hospital.

Ziel dieser Untersuchung ist es, die Inzidenz schwerer Hypoglykämien (sHypo) in den Jahren 2006/2011 bei Patienten mit CKD unter Berücksichtigung antihyperglykämischer Therapien im Versorgungsalltag zu analysieren.

Background Reported survival rates of unicondylar knee arthroplasty (UKA) vary considerably. The influences of patient characteristics and the type of implant have already been examined. This analysis investigated the influence of hospital volume on 5-year-survival rate, using administrative claims data of Germanyʼs largest health insurance provider. Methods We analysed administrative claims data for 20,946 UKAs covered by the German local healthcare funds (Allgemeine Ortskrankenkasse, AOK) between 2006 and 2012. Survival rates were estimated using Kaplan-Meier analysis. The influence of hospital case numbers on 5-year survival was analysed by means of multivariable Cox regression adjusted for patient characteristics. We estimated hazard ratios Einfluss der Fallzahl pro Klinik auf die 5-Jahres-Überlebensrate des unikondylären Kniegelenkersatzes in Deutschland Impact of Case Numbers on the 5-Year Survival Rate of Unicondylar Knee Replacements in Germany 62 Jeschke E et al. Einfluss der Fallzahl... Z Orthop Unfall 2018; 156: 62–67 Originalarbeit

Zusammenfassung Hintergrund In dieser Studie wurden die Häufigkeiten postoperativer Logopädieverordnungen bei Schilddrüsenoperationen anhand deutschlandweiter Routinedaten bestimmt, in den Kontext von Stimmbandlähmungen gesetzt und Volume-Outcome-Zusammenhänge untersucht. Material und Methoden Datengrundlage bilden bundesweite Routinedaten von AOK-Versicherten, bei denen in den Jahren 2013 bis 2015 eine Schilddrüsenoperation aufgrund einer benignen Schilddrüsenerkrankung durchgeführt wurde. Transiente und permanente Stimmbandlähmungen wurden anhand von Indikatoren und postoperative Logopädie anhand von Heilmittelverordnungen erfasst. Der Effekt des Krankenhausvolumens (Volumenquintile) auf die Verordnung von Logopädie wurde anhand multivariater logistischer Regression bestimmt. Ergebnisse Es wurden 50.676 Schilddrüsenoperationen identifiziert. Die Häufigkeit postoperativer Logopädieverordnungen betrug 6,5 %. Bei AOK-Fällen mit transienter bzw. permanenter Stimmbandlähmung betrug die Häufigkeit der Verordnungen 56,1 % bzw. 75,2 %. Die Gesamtverordnungsmenge von Logopädie nahm mit zunehmender Dauer der Stimmbandlähmung zu. Die Gesamtverordnungsmenge des Regelfalls (≥21 Einheiten Logopädie) wurde bei 0,7 % der AOK-Fälle überschritten. Gegenüber den fallzahlstärksten Krankenhäusern war das Risiko postoperativer Logopädieverordnungen mit Überschreitung der Gesamtverordnungsmenge des Regelfalls in den beiden fallzahlschwächsten Volumenkategorien signifikant erhöht (Odds Ratios: 1,2 und 1,8). Schlussfolgerung Die vorliegende Studie stellt die Versorgungsrealität im Hinblick auf die Häufigkeit der Verordnung von Logopädie nach Schilddrüsenoperationen in Deutschland dar. Zusätzlich wurde festgestellt, dass das Risiko einer postoperativen logopädischen Therapie mit Überschreitung der Gesamtverordnungsmenge des Regelfalls mit wachsender Fallzahlstärke des behandelnden Krankenhauses sinkt.

AOK-Versicherungsdaten von Menschen mit Typ 2 Diabetes (nach ICD 10; Inzidenz hochgerechnet auf die deutsche Wohnbevölkerung: 6,6 Mio. in 2006 und 7,9 Mio. in 2011) wurden auf CKD gescreent, abgegebene antihyperglykämische Medikamente wurden mittels ATC-Code identifiziert. Das mittlere Alter betrug 75,3/76,5 Jahre in 2006/2011.

Routine data from hospitals in the public healthcare system allow the analysis of large patient datasets without generating additional documentation efforts for hospitals. This study reports the frequencies of postoperative complications after thyroid surgery based on routine nationwide data. Moreover, volume-outcome relationships were investigated. Nationwide routine data from insured patients of the Local Health Insurance Fund (AOK) who underwent thyroid surgery between 2008 and 2010 were analyzed. Complications were determined based on indicators for permanent vocal cord palsy, re-bleeding with re-operations and wound infections with specific treatment. The effect of hospital volumes (volume quintiles) on the indicators was determined by multivariate logistic regression. A total of 66,902 thyroid gland operations were identified. The overall frequency of permanent vocal cord palsy was 1.5 %, re-bleeding 1.8 % and wound infections 0.4 %. In the four lowest case volume categories the risk of permanent vocal cord palsy was significantly higher compared to the highest case volume hospitals (odds ratio 1.5, 1.7, 1.7 and 2.2, respectively). This study represents the reality of healthcare for thyroid surgery in Germany. Additionally, it was determined that the risk for permanent vocal cord palsy after thyroid gland operations decreased with increasing case volumes of hospitals.

Routinedaten aus dem Gesundheitswesen erlauben die Analyse von großen Patientenkollektiven, ohne zusätzlichen Dokumentationsaufwand auf Seite der Krankenhäuser zu erzeugen. In dieser Studie wurden Häufigkeiten postoperativer Komplikationen bei Schilddrüsenoperationen anhand deutschlandweiter Routinedaten bestimmt und Volume-Outcome-Zusammenhänge untersucht.

BACKGROUND: Little real-world data is available on the comparison of different methods in surgery for lower urinary tract symptoms due to benign prostatic obstruction in terms of complications. The objective was to evaluate the proportions of TURP, open prostatectomy (OP) and laser-based surgical approaches over time and to analyse the effect of approach on complication rates.METHODS: Using data of the German local healthcare funds (Allgemeine Ortskrankenkassen (AOK)), we identified 95 577 cases with a primary diagnosis of hyperplasia of prostate who received TURP, laser vaporisation (LVP), laser enucleation (LEP) of the prostate or OP between 2008 and 2013. Univariable logistic regression was used to analyse proportions of surgical approach over time, and the effect of surgical method on outcomes was analysed by means of multivariable logistic regression.RESULTS: The proportion of TURP decreased from 83.4% in 2008 to 78.7% in 2013 (P<0.001). Relative to TURP and adjusting for age, co-morbidities, AOK hospital volume, year of surgery and antithrombotic medication, OP had increased mortality (odds ratio (OR) 1.47, P<0.05), transfusions (OR 5.20, P<0.001) and adverse events (OR 2.17, P<0.001), and lower re-interventions for bleeding (OR 0.75, P<0.001) and long-term re-interventions (OR 0.55, P<0.001). LVP carried a lower risk of transfusions (OR 0.57, P<0.001) and re-interventions for bleeding (OR 0.76, P<0.001), but a higher risk of long-term re-interventions (OR 1.43, P<0.001). LEP had increased re-interventions for bleeding (OR 1.35, P<0.01). Complications were also dependent on age and co-morbidity. Limitations include the lack of clinical information and functional results.CONCLUSIONS: OP has the greatest risks of complication despite a low re-intervention rate. LVP demonstrated favourable results for transfusion and bleeding, but increased long-term re-interventions compared with TURP, while LEP showed increased re-interventions for bleeding. Findings support a careful indication and choice of method for surgery for LUTS, taking age and co-morbidities into account.

Die meisten ergebnisbezogenen Daten über die häufigen und kostenintensiven hüftgelenknahen Frakturen leiten sich aus der externen Qualitätssicherung oder klinischen Studien ab. Die hier vorliegende Arbeit verknüpft Routine- mit Krankenkassendaten, um Langzeitergebnisse von einem Jahr und z. T. darüber hinaus abzubilden, die bisher nicht erfasst wurden. Unser Modell wurde entwickelt, um den Einfluss einer frühen Operation auf Letalität, Dekubitus und Frührevisionen zu untersuchen. Außerdem wurden die Auswirkungen auf die Lebenssituation der Betroffenen anhand von Pflegedaten überprüft.

External quality assurance for revisions of total knee arthroplasty (TKA) and total hip arthroplasty (THA) are carried out through the AQUA institute in Germany. Data are collected by the providers and are analyzed based on predefined quality indicators from the hospital stay in which the revision was performed. The present study explores the possibility to add routine data analysis to the existing external quality assurance (EQS). Differences between methods are displayed. The study aims to quantify the benefit of an additional analysis that allows patients to be followed up beyond the hospitalization itself.All persons insured in an AOK sickness fund formed the population for analysis. Revisions were identified using the same algorithm as the existing external quality assurance. Adverse events were defined according to the AQUA indicators for the years 2008 to 2011.The hospital stay in which the revision took place and a follow-up of 30 days were included. For re-operation and dislocation we also defined a 365 days interval for additional follow-up. The results were compared to the external quality control reports.Almost all indicators showed higher events in claims data analysis than in external quality control. Major differences are seen for dislocation (EQS SD: 1.87 vs. claims data [cd] SD: 2.06 %, cd+30 d: 2.91 %, cd+365 d: 7.27 %) and reoperation (hip revision: EQS SD: 5.88 % vs. claims data SD: 8.79 % cd+30 d: 9.82 %, cd+365 d: 15.0 %/knee revision: EQS SD: 3.21 % vs. claims data SD: 4.07 %, cd+30 d: 4.6 %, cd+365 d: 15.43 %). Claims data could show additional adverse events for all indicators after the initial hospital stay, rising to 77 % of all events.The number of adverse events differs between the existing external quality control and our claims data analysis. Claims data give the opportunity to complement existing methods of quality control though a longer follow-up, when many complications become evident.

BACKGROUND:One of the biggest health insurance companies in Germany (AOK, Allgemeine Ortskrankenkasse) has published new results focussing on process quality of total knee replacement in 2010. These results were published in the online portal "Weiße Liste", which is based on health insurance routine data. The German Association of Orthopeadic Surgery questions the credibility of the rating system of the "Weiße Liste". To prove the system an interdisciplinary task force was created. MATERIAL AND METHODS:The task force identified patient-specific parameters, which influence the outcome of total knee replacement based on the literature and expert opinions. Out of 907 orthopaedic departments, 4 above average and four below average were identified. The AOK was asked to provide 80 data sets for each department. These anonymised data sets could be converted into patient-specific data sets in the identified departments. Statistical analysis was performed to answer the question of whether there are differences between the below and the above average groups. RESULTS:625 cases could be investigated. We found an increased rate of postoperative complications in the below average group. There are differences between both groups in terms of factors influencing the procedure. In the below average group an increased rate of patients with one or more comorbidities and a preoperative extension lag of over 10° was found. The above average group has a higher rate of operations before the knee replacement. CONCLUSION:The results need to be proven on a larger scale. Further, prospective investigations are planned.

Zusammenfassung Hintergrund: 2010 sind durch die AOK zusätzlich zu bisherigen Veröffentlichungen im Rahmen der Weißen Liste neue Ergebnisse für die Ergebnisqualität im Bereich „Kniegelenks-Totalendoprothese bei Gonarthrose“ online veröffentlicht worden. Hierbei wurden die Kliniken im Rahmen des sogenannten „Qualitätssicherung mit Routinedaten-Verfahrens“ (QSR) beurteilt. Die Deutsche Gesellschaft für Orthopädie und orthopädische Chirurgie steht dem für das Bewertungssystem des AOK-Krankenhausnavigators genutzten QSR-Verfahren kritisch gegenüber. Es wurde eine interdisziplinäre Arbeitsgruppe gebildet, die das Verfahren überprüfen sollte. Material und Methoden: Zunächst wurden patientenspezifische Parameter identifiziert, die überwiegend gemäß Expertenkonsens auf Basis der aktuellen Literaturlage die Prozedur und das Ergebnis beeinflussen. Aus den 907 erfassten Kliniken wurden 4 überdurchschnittlich und 4 unterdurchschnittlich abschneidende identifiziert. Insgesamt sollte das Wissenschaftliche Institut der AOK (WIdO) randomisiert 80 Falldatensätze pro Klinik zur Verfügung stellen. Anhand dieser anonymisierten Datensätze konnten in den Kliniken Patienten identifiziert werden. Die statistische Auswertung sollte klären, ob ein signifikanter Unterschied zwischen den Indikatoren der Gruppen der überdurchschnittlich und unterdurchschnittlich bewerteten Kliniken vorhanden ist oder ausgeschlossen werden kann. Ergebnisse: Insgesamt konnten 625 Fälle aus den Abrechnungsdaten untersucht werden. In den unterdurchschnittlichen Kliniken finden sich vermehrt postoperative Komplikationen. Allerdings finden sich in dieser Gruppe auch mehr Patienten mit 1 oder mehr Komorbiditäten und mit einem Streckdefizit > 10°. Die überdurchschnittliche Gruppe hat einen höheren Anteil an Voroperationen. Schlussfolgerungen: Die präsentierte Untersuchung motiviert die Arbeitsgruppe, weitere größer angelegte, prospektive Studien durchzuführen.

Complication rates and secondary interventions after coronary procedures in clinical routine: 1-year follow-up based on routine data of a German health insurance company Background: Data on 1-year complication and follow-up intervention rates after coronary angiography (CA) and percutaneous coronary intervention (PCI) in German clinical routine are sparse. This analysis aims to determine these rates. Methods: The analysis uses 2009 AOK claims data. Patients were divided into 3 groups (CA, without cardiac surgery and without acute myocardial infarction (AMI) n=116.071; PCI with stenting, without AMI: n=36.685; PCI with stenting and with AMI: n=32.707). The frequency of the endpoints MACCE (mortality, AMI, stroke, TIA), CABG, PCI and CA was recorded for up to one year. Results: 1-year MACCE rates were 8.1% (CA), 9.9% (PCI without AMI) and 17.9% (PCI with AMI). Quality-relevant follow-up intervention rates in the CA group were 2.5% for CABG (after 31-365 days), 1.7% for PCI within 90 days and 3.5% for follow-up CA within 1 year. In the PCI groups, the frequencies were 1.6% (without AMI) and 2.7% (with AMI) for CABG (after 31-365 days), and 10.2% (without AMI) and 10.1% (with AMI) for PCI after 91-365 days. Conclusion: This is the first cross-sectoral routine analysis of cardiac catheters and sequential events up to one year in Germany. The actual medical care situation revealed information particularly with regard to the second and follow-up inventions, which cannot be derived directly from medical guidelines. Beyond clinical trials, knowledge can be gained which is important both for medicine as well as the politics of health services.

Aim: This study analyses the information gain achieved by additionally taking into account complications in the follow-up period instead of merely considering in-house events for a hospital-based quality measurement using the example of hip replacement.Method: The analysis was performed with anonymous statutory health insurance data (AOK) for the years 2007-2009 within the framework of the quality measurement method "Quality Assurance with Administrative Data (QSR)". It included cases of hip replacement surgery due to osteoarthritis. In order to analyse hospital-related outcome quality, 6 quality indicators were formed (revision surgery within 365 days, surgical complications within 90 days, thrombosis/pulmonary embolism within 90 days, femur fracture within 90 days, mortality within 90 days and complication index). For each hospital, the adjusted SMRs (standardised mortality or morbidity ratio) with 95% confidence intervals were calculated. The relation between the in-hospital and the follow-up SMR was analysed by Spearman's rank correlation coefficient. Furthermore, the percentage consistency of hospital SMRs categorised into quartiles on the basis of in-hospital and post-discharge events was determined.Results: A total of 154470 AOK patients from 930 hospitals were included in the analysis. The hospitals had a median overall complication rate of 11,22%. One quarter of the hospitals had complication rates of 8,18% or below. Another quarter of the hospitals had complication rates nearly twice as high (>= 15,49%). Nearly one-third of all complications occurred after the initial hospitalisation. Regarding clinic-related complications, there was little correlation between the events in the initial case and during follow-up (r<0,3) for all indicators. The order of the hospitals defined by quartiles of SMR changed significantly by adding the complications in the follow-up for the indicators considered (min 21 %, max 47% changes between quartiles). In particular, for the indicators revision and death, a change in the SMR quartile occurred in almost 50% of all hospitals.Conclusion: Quality assessment of hip replacement surgery based exclusively on in-house events is quite unreliable. On the one hand, nearly a third of all complications occur in the follow-up period. On the other hand, predicting the occurrence of post-discharge events from in-house complications of a clinic is not considered acceptable for the indicators analysed in this study.