The Kappa Paradox Explained.

Observer reliability studies for fracture classification systems evaluate agreement using Cohen's κ and absolute agreement as outcome measures. Cohen's κ is a chance-corrected measure of agreement and can range between 0 (no agreement) and 1 (perfect agreement). Absolute agreement is the percentage of times observers agree on the matter they have to rate. Some studies report a high-absolute agreement but a relatively low κ value, which is counterintuitive. This phenomenon is referred to as the Kappa Paradox. The objective of this article was to explain the statistical phenomenon of the Kappa Paradox and to help readers and researchers to recognize and prevent this phenomenon.

Direct discharge for children with a greenstick or torus fracture of the wrist is a non-inferior satisfactory solution to traditional treatment.

PURPOSE: Direct Discharge protocols (DD) can alleviate strain on healthcare systems by reducing routine outpatient follow-up. These protocols include low-complex musculoskeletal injuries, such as isolated greenstick fractures or torus fractures of the wrist in children. While there is consensus on the effectiveness of DD, there is a lack of injury-specific powered studies. This study compares treatment satisfaction between DD and traditional treatment in children with a greenstick fracture or torus fractures of the wrist. METHODS: Children with isolated torus or greenstick fractures of the distal radius or ulna were eligible for inclusion before (pre-DD cohort) and after (DD cohort) the implementation of DD in four hospitals. Traditionally, patients receive a (soft) cast and minimally one routine outpatient follow-up appointment. With DD, patients are discharged directly from the ED after receiving a brace and information, summarized in a smartphone app and a helpline for questions during recovery. The primary outcome was patient or proxy treatment satisfaction (0 to 10), and a power analysis was performed to assess non-inferiority. Secondary outcomes included complications, functional outcomes measured in Patient-Reported Outcomes Measurement Information System Upper Extremity (PROMIS UE), primary healthcare utilisation, and secondary healthcare utilisation (follow-up appointments and imaging). RESULTS: In total, 274 consecutive children were included to analyse the primary endpoint. Of these, 160 (58%) were male with a median age of 11 years (IQR 8 to 12). Pre-DD and DD treatment satisfaction did not vary statistically significantly for greenstick fractures (p = 0.09) and torus fractures (p = 0.93). No complications were observed. PROMIS UE showed no statistically significant differences before and after implementation of direct discharge protocol for torus (p = 0.99) or greenstick (p = 0.45) fractures. Secondary healthcare utilisation regarding follow-up was significantly lower in the DD-torus cohort compared to the pre-DD torus cohort, with a mean difference (MD) of - 1.00 follow-up appointments (95% Confidence Interval (CI) - 0.92 to - 1.13). Similar results were found in the pre DD-greenstick cohort compared to the pre-DD-greenstick cohort (MD): - 1.17 follow-up appointments, 95% CI - 1.09 to - 1.26). CONCLUSION: Direct Discharge is non-inferior to traditional treatment in terms of treatment satisfaction for paediatric patients with greenstick or torus fractures of the wrist compared to children treated with rigid immobilisation and routine follow-up. Furthermore, the results demonstrate no complications, comparable functional outcomes, and a statistically significant reduction of secondary healthcare utilisation, making DD a good solution to cope with strained resources for children with an isolated greenstick fracture or torus fracture of the wrist.

Study protocol: non-displaced distal radial fractures in adult patients: three weeks vs. five weeks of cast immobilization: a randomized trial.

BACKGROUND: Up to 30% of patients suffer from long-term functional restrictions following conservative treatment of distal radius fractures. Whether duration of cast immobilisation influences functional outcome remains unclear. METHODS/DESIGN: The aim of the study is to evaluate whether the duration of immobilization of non or minimally displaced distal radial fractures can be safely reduced. We will compare three weeks of plaster cast immobilization with five weeks of plaster cast immobilization in adult patient with non or minimally displaced distal radial fractures. STUDY DESIGN: a prospective randomized clinical trial. STUDY POPULATION: adult (>18 years) (independent in activities of daily living) patients with a non/minimal displaced distal radius fracture (dorsal angulation <15°, volar tilt <20°, radial inclination >15°, ulnar positive variance <5 mm and an articular step off <2 mm). INTERVENTION: three weeks of plaster cast immobilization versus five weeks of plaster cast immobilization.Main study parameters: primary outcome parameters: Patient related wrist evaluation (PRWE) Quick Disability of Arm, Shoulder and Hand (QUICKDASH) score after a one year follow-up, and secondary parameters: range of motion, pain level (VAS) and complications. DISCUSSION: The expectation of this study is that shorter duration of plaster cast immobilisation is beneficial for the patient with a distal radius fracture. This risk of specific complications is low and generally similar in both treatment options. Moreover, the burden of the study is not much higher compared to standard treatment. Follow-up is standardized according to current trauma guidelines. Literature indicates that both treatment options from the study are accepted for displaced distal radius fractures. No clear advantage for one treatment options is found at present in the literature, although there is no level I evidence present. This trial will provide level-1 evidence for the comparison of consolidation and functional outcome between two treatment options for non-displaced distal radial fractures. The gathered data may support the development of a clinical guideline for conservative treatment of distal radial fractures. TRIAL REGISTRATION: Netherlands National Trial Register NTR3552.

Developing process guidelines for trauma care in the Netherlands for severely injured patients: results from a Delphi study.

BACKGROUND: In organised trauma systems the process of care is the key to quality. Nevertheless, the optimal process of trauma care remains unclear due to lack of or inconclusive evidence. Because monitoring and improving the performance of a trauma system is complex, this study aimed to develop consensus-based process guidelines for trauma care in the Netherlands for severely injured patients. METHODS: A five-round Delphi study was conducted with 141 participants that represent all professions involved in trauma care. Sensitivity analyses were carried out to evaluate whether consensus extended across all professions and to detect possible bias. RESULTS: Consensus was reached on 21 guidelines within 4 categories: timeliness, actions, competent teams and interdisciplinary process. Timeliness guidelines set specific critical limits and definitions for 10 time intervals in the time period from an emergency call until the patient leaves the trauma room. Action guidelines reflect aspects of appropriate care and strongly rely on the international Advanced Trauma Life Support principles. Competence guidelines include flow charts to assess the competence of prehospital and emergency department teams. Essential to competent teams are education and experience of all team members. The interdisciplinary process guideline focuses on cooperation, communication and feedback within and between all professions involved. Consensus was extended across all professions and no bias was detected. CONCLUSIONS: In this Delphi study, a large expert panel agreed on a set of guidelines describing the optimal process of care for severely injured trauma patients in the Netherlands. In addition to time intervals and appropriate actions, these guidelines emphasise the importance of team competence and interdisciplinary processes in trauma care. The guidelines can be seen as a description of a best practice and a new field standard in the Netherlands. The next step is to implement the guidelines and monitor the performance of the Dutch trauma system based on the guidelines.

Historical Treatment Results of Pelvic Ring Fractures: A 12-year Cohort Study.

BACKGROUND: Since the Academic Medical Center Amsterdam was appointed as a level-1 trauma center in July 1997, the number of polytrauma patients who were presented has increased. This stimulated us to perform a retrospective analysis on the treatment results of patients with a pelvic ring fracture and to evaluate our treatment strategies. MATERIALS AND METHODS: A chart review of all patients with a partially stable fracture (Tile/AO type B) or an unstable fracture (Tile/AO type C) was performed. All patients presented between 1 January 1990 and 31 December 2001 were included. Two historical groups (1990-1997 and 1998-2001) were formed. General demographics, treatment method, complications, re-operations, length of hospital stay and anatomic results were recorded for all patients. RESULTS: Fifty-two patients were included in group 1 and 65 patients in group 2. There was a lower mortality in group 2. The B-fractures were treated either conservatively (group 1 83.3% vs. group 2 73.8%), by external fixation (16.7 vs. 9.5%) or by ORIF (0 vs. 16.7%). C-fractures were treated by ORIF in 32.1 versus 82.6%, by external fixation in 28.6 versus 4.4% and conservatively 39.3 versus 13.0%, respectively. Fracture healing with less than 10 mm displacement was achieved in 58.3 versus 78.6% for the B-fractures, while this was achieved in 42.9 versus 73.9% in the C-fractures. Group 2 showed significantly fewer complications. CONCLUSION: Evaluating two consecutive patient groups shows an increase in the number of fractures. A more aggressive surgical treatment has lead to lower mortality, improved anatomical reduction, and lower rate of complications.