No added value of the age-adjusted D-dimer cut-off to the YEARS algorithm in patients with suspected pulmonary embolism.

Essentials Imaging is warranted in the majority of patients to confirm or rule out pulmonary embolism (PE). The age-adjusted D-dimer (ADJUST) reduced the number of required imaging tests in patients ≥ 50 years. The YEARS algorithm was designed to improve the efficiency in patients with suspected PE. There was no added value of implementing ADJUST in the YEARS algorithm in our cohort. SUMMARY: Background The YEARS algorithm was designed to simplify the diagnostic work-up of pulmonary embolism (PE) and to reduce the number of necessary computed tomography pulmonary angiography (CTPA) scans. An alternative strategy to reduce the number of CTPAs is the age-adjusted D-dimer cut-off (ADJUST) in patients aged 50 years or older. We aimed to investigate whether a combination of both diagnostic strategies might save additional CTPAs. Methods The YEARS algorithm consists of three items (clinical signs of deep venous thrombosis, hemoptysis, 'PE most likely diagnosis') with simultaneous D-dimer testing using a pre-test dependent threshold. We performed a post hoc analysis in 3465 patients managed according to YEARS to compare the number of patients managed without CTPA scans and associated diagnostic failures in hypothetical scenarios with different YEARS-ADJUST combinations. Results Following the YEARS algorithm, 1651 patients (48%) were managed without CTPA; PE was diagnosed in 456 (13%) patients at baseline and 18 patients with initial normal testing suffered venous thromboembolism (VTE) during 3-month follow-up (failure rate 0.61%; 95% confidence interval [CI], 0.36-0.96). If ADJUST had been fully integrated in YEARS, 1627 patients (47%) would have been managed without CTPA (absolute decrease of 0.69%; 95% CI -1.7 to 3.0), at cost of four additional missed PE diagnoses at baseline, for a projected 3-month VTE failure rate of 0.75% (95% CI, 0.49-1.13). None of the other studied scenarios showed relevant improvements in efficiency as well, but all led to more missed diagnoses. Conclusion In our cohort, there was no added value of implementing ADJUST in the YEARS algorithm.

Effects of large herbivores on grassland arthropod diversity.

Both arthropods and large grazing herbivores are important components and drivers of biodiversity in grassland ecosystems, but a synthesis of how arthropod diversity is affected by large herbivores has been largely missing. To fill this gap, we conducted a literature search, which yielded 141 studies on this topic of which 24 simultaneously investigated plant and arthropod diversity. Using the data from these 24 studies, we compared the responses of plant and arthropod diversity to an increase in grazing intensity. This quantitative assessment showed no overall significant effect of increasing grazing intensity on plant diversity, while arthropod diversity was generally negatively affected. To understand these negative effects, we explored the mechanisms by which large herbivores affect arthropod communities: direct effects, changes in vegetation structure, changes in plant community composition, changes in soil conditions, and cascading effects within the arthropod interaction web. We identify three main factors determining the effects of large herbivores on arthropod diversity: (i) unintentional predation and increased disturbance, (ii) decreases in total resource abundance for arthropods (biomass) and (iii) changes in plant diversity, vegetation structure and abiotic conditions. In general, heterogeneity in vegetation structure and abiotic conditions increases at intermediate grazing intensity, but declines at both low and high grazing intensity. We conclude that large herbivores can only increase arthropod diversity if they cause an increase in (a)biotic heterogeneity, and then only if this increase is large enough to compensate for the loss of total resource abundance and the increased mortality rate. This is expected to occur only at low herbivore densities or with spatio-temporal variation in herbivore densities. As we demonstrate that arthropod diversity is often more negatively affected by grazing than plant diversity, we strongly recommend considering the specific requirements of arthropods when applying grazing management and to include arthropods in monitoring schemes. Conservation strategies aiming at maximizing heterogeneity, including regulation of herbivore densities (through human interventions or top-down control), maintenance of different types of management in close proximity and rotational grazing regimes, are the most promising options to conserve arthropod diversity.

Cardiopulmonary resuscitation preferences in Dutch community-dwelling and hospitalized elderly people: an interaction between gender and quality of life.

OBJECTIVE: To study the effects of information, gender, quality of life, and hospitalization on cardiopulmonary resuscitation (CPR) preferences and on the wish for information and participation in CPR discussions. METHODS: Seventy-five community-dwelling inhabitants of the city of Leiden and 45 consecutive patients in two hospitals in Leiden, The Netherlands, aged 75 years or older, were interviewed about their CPR preferences in their current states of health and in three hypothetical scenarios. Health-related quality of life (QOL) was assessed in separate items. The subjects were asked about their wishes for information and participation in CPR discussions. RESULTS: The chances of surviving CPR were overestimated. After receiving accurate information, 65% of the subjects, more women than men, did not want CPR. Overall QOL did not differ between men and women. Concerning the separate QOL items, men's CPR preferences were more associated with pain, whereas women's were more associated with being impaired in physical functioning and daily and social activities. CPR preferences in the current state of health did not differ significantly between community-dwelling and hospitalized participants. Although only 6% of all participants had ever discussed CPR with their doctors, 70% indicated they wanted routine CPR discussions (either when in good health at home or upon hospital admission), and 61% preferred to make the final decision about CPR themselves. CONCLUSIONS: CPR preferences are affected by different QOL items in men and women. CPR preferences in the current state of health do not differ between hospitalized and community-dwelling elderly people. As the majority of elderly people want CPR discussions, they should be involved in decision making concerning CPR.