Discussion
Primary aim of this study was to compare clinical effectiveness between the common medical rehabilitation approach after p-THA in Germany and the common approach in the Netherlands for working-age patients against the background of the prognosis that the majority of p-THA patients will be from the working-age population [Looking at clinical effectiveness, data collected in the present study confirm the hypothesis that the German procedure results in a significantly higher proportion of patients (65.6% of German vs. 47.5% of Dutch participants) who are satisfied 12 weeks after p-THA and who have benefited from surgery and subsequent follow-up treatment. At 6 months postoperatively, German patients were still more satisfied than Dutch patients (69.4% vs. 58.1%). Overall, German patients are twice as likely to benefit from surgery and related medical rehabilitation measures and thus achieve greater satisfaction.The German cohort scored significantly better on self-reported function. Some of these differences were clinically relevant, especially on the subdomains of the SF-36, namely Füssenich et al. also compared the usual p-THA treatment in the Netherlands to the German approach [In terms of cost analyses, the present study should and can only provide a first impression. Cost comparisons are challenging because of the substantial between-country differences in socioeconomic context and essential structures of the healthcare system. On one side of the border, for example, there are certain specialists, medical professionals and/or therapeutic approaches that do not exist in the other country (e.g., outpatient specialists, land-based and/or water-based medical rehabilitation). For this reason, all information on resource use was collected via a patient self-reported questionnaire, which was partly adapted to the respective system. Where precise monetary evaluation rates could not be determined on the German side, data from the OECD were tapped, with the OECD health expenditure of both countries used as a share of GDP in each case to reflect country-specific prices of healthcare facilities. A more accurate impression could only be obtained if all costs were available without restriction in both countries.The German approach appears considerably more expensive than the Dutch, given the much more intensive multimodal and interdisciplinary medical p-THA rehabilitation in Germany. The German approach is also more expensive given the higher productivity losses due to work absenteeism. This can be explained by a higher amount of regular weekly working hours and higher wage costs in Germany. Overall, considering this study’s total population, medical rehabilitation costs in connection with p-THA are almost twice as high in Germany (45%) as in the Netherlands. However, when comparing only patients who are actively employed a more balanced picture emerges where the costs in Germany are only about 20% higher than in the Netherlands.As mentioned, the average weekly working hours of German patients are higher than those of Dutch patients, as is the hourly wage in Germany (Additional file For clinical practice, the present study’s results suggest that it must be questioned whether it wouldn’t be useful for the Netherlands to adopt the German approach to medical rehabilitation after p-THA, or at least aspects of it. In the 1970s, when the first p-THAs were implanted, most patients were already of advanced retirement age and had a lower activity level [The present study must be evaluated, given its limitations. Among these is that the concept of common p-THA follow-up in the Netherlands is difficult to define, as implementation of physiotherapeutic measures can vary widely from patient to patient. Both the Dutch Orthopaedic Association and the Royal Dutch Physiotherapy Association recommend continuous physiotherapy follow-up after p-THA and hospital discharge to correct remaining dysfunctions; increase muscle strength, mobility, and stability; harmonize gait; and minimize limitations in activities of daily living [Another limitation could be that on the German side only those patients were included who agreed at study enrollment to have their rehabilitation treatment in the cooperating rehabilitation center, which represents a possible selection bias. However, it should be noted that the evidence-based rehabilitation standards defined for p-THA by the DRV apply equally to all rehabilitation facilities and implementation is standardized. In this respect, it can be assumed that the effects would not have been substantial even if such a bias had existed.Another limitation is that no comparison between German and Dutch patients was possible regarding payment of wage replacement benefits, since only a minority of German patients could provide information on receipt of such benefits and Dutch patients were not asked about their income during their absence from work. The cost comparison is limited by the fact that early rehabilitation services at the hospital were not specifically considered in the present cost analysis. German patients stay longer at the hospital postoperatively and thus also receive physiotherapeutic services longer in the sense of early rehabilitation compared to the Dutch.Future studies should follow p-THA patients from both countries and systems over a longer period to evaluate the long-term effects of the respective follow-up treatments on functional capacity, activities, and participation. This should include an examination of the influence of cultural differences on rehabilitation outcomes. Since the economic comparison of the medical rehabilitation approaches in the current study can only give a first impression, it would also be important to conduct studies that shed further light on the economic aspect. Such studies should include larger cohorts and follow them over a longer period.