Impact of evidence-based guidelines on healthcare utilisation and costs for disc related sciatica in the Netherlands: a population-based, cross-sectional study.

OBJECTIVE: The aim of this study was to assess the impact of high-quality evidence supporting surgical treatment of lumbar disc herniation (LDH) on healthcare practice in the Netherlands by examining changes in healthcare utilisation, including the timing of surgery, and the healthcare costs for patients with LDH. DESIGN: A retrospective, cross-sectional study was performed using population-based, longitudinal data obtained from the Dutch Healthcare Authority (2007-2020) and NIVEL's primary care (2012-2020) administrative databases. SETTING: The study was conducted within the healthcare system of the Netherlands. PARTICIPANTS: We included adults (≥18 years) who visited a Dutch hospital or a general practitioner (GP) for lumbar degenerative disc disease. Patients with LDH were identified based on registered diagnosis code, type of surgery (discectomy) and age (<56 years). MAIN OUTCOME MEASURES: The primary outcome measure was the difference in the annual number of LDH procedures following the publication of evidence-based guidelines in 2009 (comparing the periods 2007-2009 to 2017-2019). Secondary outcome measures focused on the timing of surgery and associated healthcare costs. To validate the outcomes, secondary outcomes also include the number of discectomies and the number of procedures in the younger age group (discectomies, laminectomies, and fusion surgery). RESULTS: The number of patients suffering from LDH increased from 55 581 to 68 997 (+24%) between 2007 and 2019. A decrease was observed in the annual number of LDH procedures (-18%), in the number of discectomies (-22%) and in the number of procedures for patients aged <56 years (-18%). This resulted in lower healthcare costs by €10.5 million annually. In 2012, 31% of all patients <56 years had surgery before 12 weeks from diagnosis at the GP, whereas 20% did in 2019. CONCLUSIONS: Healthcare utilisation for LDH changed tremendously in the Netherlands between 2007 and 2020 and seemed to be associated with the publication and implementation of evidence-based guidelines. The observed decrease in the number of procedures has been accompanied by a corresponding reduction in healthcare costs. These findings underscore the importance of adhering to evidence-based guidelines to optimise the management of patients with LDH.

Selection for restraint in competitive ability in spatial competition systems.

The absence of 'super competitors' in nature is usually attributed to organisms facing trade-offs in resource allocation. Here we identify another mechanism, dependent on indirect interactions among species and non-random spatial organization, in which selection favours restraint in competitive ability. In simple spatial models of a three-species intransitive network, indirect interactions favour slower growth and selection limits the difference in growth rate among species. The mechanism involves a trade-off between selection at the individual level, which selects for increased growth rate, and at the community level, which acts to limit growth rate to less than the maximum possible. If the difference in growth rates among species becomes too large, then the community becomes unstable and collapses to a monoculture of the slowest growing species. The mechanism requires both the intransitive network structure and self-organized spatial structure in the system. Similar behaviours arise in more complex systems of more than three species, and where there are reversals in interaction outcomes between species pairs. The work suggests that spatial self-structuring, indirect interactions and selection acting on community properties can be important in evolution. It provides a partial explanation of the high level of species coexistence and apparent restraint in interspecific interactions evident in some assemblages of sessile marine colonial organisms.