Use of ROC curve analysis for prediction gives fallacious results: Use predictivity-based indices.

ABSTRACT: The area under the ROC curve is frequently used for assessing the predictive efficacy of a model, and the Youden index is commonly used to provide the optimal cut-off. Both are misleading tools for predictions. A ROC curve is drawn for the sensitivity of a quantitative test against its (1 - specificity) at different values of the test. Both sensitivity and specificity are retrospective in nature as these are indicators of correct classification of already known conditions. They are not indicators of future events and are not valid for predictions. Predictivity intimately depends on the prevalence which may be ignored by sensitivity and specificity. We explain this fallacy in detail and illustrate with several examples that the actual predictivity could differ greatly from the ROC curve-based predictivity reported by many authors. The predictive efficacy of a test or a model is best assessed by the percentage correctly predicted in a prospective framework. We propose predictivity-based ROC curves as tools for providing predictivities at varying prevalence in different populations. For optimal cut-off for prediction, in place of the Youden index, we propose a P-index where the sum of positive and negative predictivities is maximum after subtracting 1. To conclude, for correctly assessing adequacy of a prediction models, predictivity-based ROC curves should be used instead of the usual sensitivity-specificity-based ROC curves and the P-index should replace the Youden index.

Onboarding of siponimod in secondary progressive multiple sclerosis patients in Australia: Novel, real-world evidence from the MSGo digital support programme.

Background: Siponimod is approved for use in people with secondary progressive multiple sclerosis (pwSPMS). An integrated digital platform, MSGo, was developed for pwSPMS and clinicians to help navigate the multiple steps of the pre-siponimod work-up. Objective: To explore real-world onboarding experiences of siponimod amongst pwSPMS in Australia. Methods: Retrospective, non-interventional, longitudinal, secondary analysis of data extracted from MSGo (20 April 2022). The primary endpoint was the average time for siponimod onboarding; secondary endpoints were adherence and sub-group analyses of variables influencing onboarding. Results: Mixed-cure modelling estimated that 58% of participants (N = 368, females 71%, median age of 59 years) registered in MSGo would ever initiate siponimod. The median time to initiation was 56 days (95% CI [47-59] days). Half of the participants cited 'waiting for vaccination' as the reason for initiation delay. Cox regression analyses found participants with a nominated care partner had faster onboarding (HR 2.1, 95% CI [1.5-3.0]) and were more likely to continue self-reporting daily siponimod dosing than were those without a care partner (HR 2.2, 95% CI [1.3-3.7]). Conclusions: Despite the limitations of self-reported data and the challenges of the COVID-19 pandemic, this study provides insights into siponimod onboarding in Australia and demonstrates the positive impact of care partner support.

Individual perceptions of community efficacy for non-communicable disease management in twelve communities in China: cross-sectional and longitudinal analyses.

OBJECTIVES: This objective of this study was to use empirical data to assess cross-sectional variation singular and changes over time in community efficacy for non-communicable diseases (NCDs) management (COEN) and to examine individual factors associated with changes in COEN. STUDY DESIGN: This was a longitudinal observational study. METHODS: Participants with hypertension and diabetes were randomly selected from 12 communities from three cities in eastern China, and a baseline survey and a 1-year follow-up were conducted. The COEN scale has five dimensions: community physical environment (CPE), behavioral risk factors (BRF), mental health and social relationships (MHSR), community health management (CHM), and community organisations and activities (COA). Mixed-effects models were used to investigate the change in COEN over time and the association between individual factors and changes in COEN. RESULTS: COEN scores showed significant variation singular among the 12 communities (P < 0.001) at the baseline. In the mixed-effects model, CPE (ß coefficient: 1.62, P < 0.001), BRF (0.90, P < 0.001), MHSR (0.86, P < 0.001), CHM (0.46, P < 0.001), and total scores (ß = 3.57, P < 0.001) increased significantly over time. The changes in COEN were associated with individual characteristics (e.g., older, men, more educated). CONCLUSIONS: Cross-sectional variations and changes over time in COEN demonstrated the utility of a sensitive instrument. Factors such as age, gender, marriage, education level, and employment may affect the financial and social resources assignment for NCD management. Our findings suggest that further high-quality studies are needed to better evaluate the effect of community empowerment on the prevention and control of NCDs.

The minimum effective dose (ED90) of prophylactic oxytocin infusion during cesarean delivery in patients with and without obesity: an up-down sequential allocation dose-response study.

BACKGROUND: Obesity is associated with greater oxytocin requirement during labor induction or augmentation. There are scant data exploring the intra-operative requirement during cesarean delivery in patients with obesity, and none comparing it with those without obesity. We evaluated the minimum effective dose (ED90) of an oxytocin infusion to achieve adequate uterine tone during cesarean delivery in patients with and without obesity. METHODS: Patients (body mass index ≥30 kg/m2 represented patients with obesity) undergoing cesarean delivery using subarachnoid block were included. This prospective dual-arm dose-finding study used a 9:1 biased sequential allocation design. Oxytocin infusion was initiated at 13 IU/h at cord clamping in the first patient of each group. Uterine tone was graded as satisfactory or unsatisfactory by the obstetrician four minutes after initiation of the infusion. The dose of oxytocin infusion for subsequent patients was determined according to the response of the previous patient in the group. Oxytocin-associated side effects were evaluated. Dose-response data for the groups was evaluated using log-logistic function and ED90 estimates derived from fitted equations using the delta method. RESULTS: The ED90 of oxytocin was significantly higher for patients with obesity (n = 40) compared with those without obesity (n = 40) [25.7 IU/h, 95% CI 18.6 to 32.9) vs. 16.6 IU/h, 95% CI 14.9 to 18.3)]; relative ratio 1.55 [95% CI 1.09 to 2.01] (P = 0.019). CONCLUSIONS: Patients with obesity require a higher intra-operative oxytocin infusion dose rate to achieve a satisfactorily contracted uterus after fetal delivery when compared with patients without obesity.

Calculation of effective dose of phenylephrine bolus for treatment of post-spinal hypotension in pre-eclamptic patients undergoing caesarean section - a non-randomised controlled trial.

BACKGROUND: Patients with pre-eclampsia require smaller vasopressor doses compared with those with normotension for management of post-spinal hypotension during caesarean section. However, the literature has little evidence as to the phenylephrine dose required for patients with pre-eclampsia. METHODS: Fifty patients, with either pre-eclampsia or normotension, and developing post-spinal hypotension during caesarean section under spinal anaesthesia, were studied. Women in both groups did not receive prophylactic vasopressors. The first patient in each group received phenylephrine 50 µg to treat the first episode of hypotension, defined as fall of systolic blood pressure ≥20% from baseline or an absolute value <100 mmHg. If hypotension was corrected within one minute it was considered a 'success'. The doses for the subsequent patients were determined by responses to all previous patients, according to a variation of Narayana's rule for the up-down sequential allocation method. RESULTS: The 95% effective dose (ED95) and 50% effective dose (ED50) of phenylephrine was 41.7 µg (95% CI 33.8 to 49.6 µg) and 29.1 µg (95% CI 26.0 to 32.2 µg) respectively in the pre-eclampsia group, and 64.9 µg (95% CI 54.1 to 75.7 µg) and 47.3 µg (95% CI 39.7 to 54.9 µg) respectively in the normotensive group. The proportionate reduction in phenylephrine dose ranged from 33% (95% CI 18 to 44%) to 40% (95% CI 19 to 52%). CONCLUSION: Patients with pre-eclampsia may need a 33% to 40% reduction in the first phenylephrine bolus dose, compared with patients with normotension, for the treatment of the first episode of post-spinal hypotension.

Designing Calcium Silicate Cements with On-Demand Properties for Precision Endodontics.

Calcium silicate (C3S) cements are available in kits that do not account for patients' specific needs or clinicians' preferences regarding setting time, radiopacity, mechanical, and handling properties. Moreover, slight variations in powder components and liquid content affect cement's properties and bioactivity. Unfortunately, it is virtually impossible to optimize several cement properties simultaneously via the traditional "one variable at a time" strategy, as inputs often induce trade-offs in properties (e.g., a higher water-to-powder ratio [W/P] increases flowability but decreases mechanical properties). Herein, we used Taguchi's methods and genetic algorithms (GAs) to simultaneously analyze the effect of multiple inputs (e.g., powder composition, radiopacifier concentration, and W/P) on setting time, pH, flowability, diametral tensile strength, and radiopacity, as well as prescribe recipes to produce cements with predicted properties. The properties of cements designed with GAs were experimentally tested, and the results matched the predictions. Finally, we show that the cements increased the genetic expression of odonto/osteogenic genes, alkaline phosphatase activity, and mineralization potential of dental pulp stem cells. Hence, GAs can produce cements with tailor-made properties and differentiation potential for personalized endodontic treatment.

Effect of Tooth Loss on Cognitive Function among Older Adults in Singapore.

Evidence suggests a longitudinal association between tooth loss and cognitive function. However, the temporality of this association is not well understood. We investigated the effect of several emulated tooth loss prevention scenarios on cognitive function. We used data from 3 waves (baseline: 2009, second wave: 2011-2012, and third wave: 2015) of the Panel on Health and Ageing of Singaporean Elderly (PHASE). PHASE targeted older adults, aged ≥60 y, in Singapore. Number of teeth was used as a time-varying exposure (baseline, second wave). Cognitive function (Short Portable Mental Status Questionnaire score) in the third wave was assessed as the outcome. Multiple time-invariant (baseline) and time-varying (baseline and second wave) covariates were included. The "longitudinal modified treatment policy approach" combined with targeted minimum loss-based estimation was used to define and estimate additive effects of emulated tooth loss prevention scenarios. Emulated scenarios were the following: what if edentate people retained 1 to 4 teeth (scenario 1), what if those with <5 teeth retained 5 to 9 teeth (scenario 2), what if those with <10 teeth retained 10 to 19 teeth (scenario 3), and what if everyone retained ≥20 teeth (scenario 4)? A total of 1,516 participants, excluding those with severe cognitive impairment, were included (male: 41.6%). The mean age at baseline was 70.6 y (SD = 7.1). The mean SPMSQ score at baseline was 2.06 (SD = 0.02) for edentulous, 1.55 (SD = 0.04) for 1 to 4 teeth, 1.61 (SD = 0.03) for 5 to 9 teeth, 1.73 (SD = 0.02) for 10 to 19 teeth, and 1.71 (SD = 0.02) for ≥20 teeth. Additive effect of hypothetical intervention gradually increased with intensity of prevention from scenario 1 to scenario 4 (scenario 1: -0.02 [95% CI, -0.08 to 0.04], scenario 2: -0.05 [95% CI, -0.11 to -0.00], scenario 3: -0.07 [95% CI, -0.14 to -0.00], scenario 4: -0.15 [95% CI, -0.23 to -0.06]). Emulated tooth loss prevention interventions were associated with better cognitive function score. Therefore, preventing tooth loss could potentially benefit maintenance of cognitive function among older adults.

Material risk: vitreoretinal surgery, evisceration, enucleation and sympathetic ophthalmia-where are we currently?

Sympathetic ophthalmia (SO) is known to occur after severe penetrating eye injury, evisceration and even enucleation surgery. Recent evidence suggests that a greater risk lies after multiple vitreoretinal procedures. The risk of SO following evisceration is only minimally greater than that following enucleation surgery. This review evaluates literature on SO to date and provides figures for the risk of developing SO for the purposes of the consent process. The issue of SO and Material Risk following vitreoretinal surgery is reviewed and figures for the purposes of consent are outlined. This is of particular relevance for patients in whom the contralateral eye is and will likely remain the better seeing eye. Sympathetic ophthalmitis is known to occur after severe penetrating eye injury, after evisceration and enucleation. More recently, sympathetic ophthalmitis has been recognised to occur after vitreoretinal surgery. This article reviews the evidence on material risk when consenting patients for elective and emergency eye procedures after ocular trauma or surgery. When a globe needs to be removed because of irreparable ocular injury, previous publications dictated the procedure to be an enucleation because of the fear of an increased risk of SO after an evisceration. Perhaps the issue of material risk of sympathetic ophthalmia (SO) remains over-emphasised by ophthalmic plastic surgeons and under-recognised by vitreoretinal surgeons during the consent process for evisceration, enucleation and vitreoretinal surgery. Antecedent trauma and number of previous surgeries may actually be a more significant risk factor than the type of eye removal. Recent medicolegal cases also help us understand the importance of the discussion of this risk. We present our current understanding of the risk of SO after different procedures and suggest how this information may be included in a patient consent.

Is Follow-up Co-Morbidity Assessment via Laboratory Investigations in Older High Energy Trauma Patients Justified? - A Prospective-Retrospective Study.

Introduction: The objective of the current study was to test our hypothesis that older patients sustaining high energy trauma need to be evaluated for their comorbidities similar to geriatric patients sustaining low energy trauma. Materials and methods: This study was a retrospective-prospective analysis of 173 patients of more than 50 years of age enrolled between November 2017 and December 2018. Herewith, we have compared retrospectively collected laboratory investigations of 124 fragility fracture patients with prospectively collected laboratory investigations of 49 patients with high energy trauma. The laboratory investigations, including the liver function tests, renal function tests, indices of calcium metabolism, serum electrolytes, complete blood counts, and bone mineral density (BMD) scores. Results: Both groups were similar to each other as far as baseline demographic characteristics were concerned. The proportion of female patients and patients with non-osteoporotic range BMD (T-score >-2.5) was significantly higher in the high-energy fracture group (P value <0.05). Hypoalbuminemia (<3.4gm/dl) 17.3%, abnormalities sodium (<135mmol/L or >148mmol/L) 23.2%, Anaemia (<10g/dl) 12.7%, Hypercalcemia (>10.4mg/dl) 16.3%, Vitamin D deficiency (<20ng/ml) 17.3% are the common laboratory abnormality found in study population. No statistically significant difference was found among the two groups in terms of laboratory investigation abnormalities. Conclusion: The laboratory investigation abnormality in an older patient with a clinical fracture is independent of the mechanism of injury. The results of the current study emphasise the need for a comprehensive laboratory workup in older patients with either high- energy fractures or fragility fractures.

Intensive Blood Pressure Management Preserves Functional Connectivity in Patients with Hypertension from the Systolic Blood Pressure Intervention Randomized Trial.

BACKGROUND AND PURPOSE: The Systolic Blood Pressure Intervention (SPRINT) randomized trial demonstrated that intensive blood pressure management resulted in slower progression of cerebral white matter hyperintensities, compared with standard therapy. We assessed longitudinal changes in brain functional connectivity to determine whether intensive treatment results in less decline in functional connectivity and how changes in brain functional connectivity relate to changes in brain structure. MATERIALS AND METHODS: Five hundred forty-eight participants completed longitudinal brain MR imaging, including resting-state fMRI, during a median follow-up of 3.84 years. Functional brain networks were identified using independent component analysis, and a mean connectivity score was calculated for each network. Longitudinal changes in mean connectivity score were compared between treatment groups using a 2-sample t test, followed by a voxelwise t test. In the full cohort, adjusted linear regression analysis was performed between changes in the mean connectivity score and changes in structural MR imaging metrics. RESULTS: Four hundred six participants had longitudinal imaging that passed quality control. The auditory-salience-language network demonstrated a significantly larger decline in the mean connectivity score in the standard treatment group relative to the intensive treatment group (P = .014), with regions of significant difference between treatment groups in the cingulate and right temporal/insular regions. There was no treatment group difference in other networks. Longitudinal changes in mean connectivity score of the default mode network but not the auditory-salience-language network demonstrated a significant correlation with longitudinal changes in white matter hyperintensities (P = .013). CONCLUSIONS: Intensive treatment was associated with preservation of functional connectivity of the auditory-salience-language network, while mean network connectivity in other networks was not significantly different between intensive and standard therapy. A longitudinal increase in the white matter hyperintensity burden is associated with a decline in mean connectivity of the default mode network.

Modern cemented Furlong hemiarthroplasty: Are dislocations rates better?

BACKGROUND: Dislocation following hip hemiarthroplasty is a major complication with increased mortality and morbidity. Data looking at dislocation following contemporary bipolar stems are lacking in literature. METHODS: Retrospective review of our prospective national hip fracture database over a two-year period. Group 1 comprised of consecutive patients receiving bipolar Furlong prosthesis (N222) while Group 2 was made up of a historical cohort (uncemented; N254). Clinical and radiological records were reviewed to determine dislocation rates, causes and associative factors of dislocations. Data were analysed using SPSS. RESULTS: Following 476 hemiarthroplasties performed during the study period, 12 (2.5%) dislocations were reported (eight in Group 1; four in Group 2). There was no significant difference in dislocation rates (3.6% vs 1.6%) between groups (p = 0.159). Subgroup analysis of Group 1 demonstrated a significant difference in dislocations with Furlong cemented (6%) as compared with Furlong uncemented (0%) hemiarthroplasties (p = 0.024). Following dislocation, death rates increased to 8.3% from 1.7% in both groups. CONCLUSION: There is a statistically significant increase in dislocation rate following use of cemented Furlong prosthesis when compared to similar uncemented prosthesis at the same treatment period. However, when compared to traditional uncemented prosthesis, there is no difference in dislocation rates.

Sustainable multi-trait selection index based on production, reproduction, and health traits for genetic improvement of Murrah buffaloes.

Selection of Murrah buffaloes based on production, reproduction, and health traits play an important role in sustainable genetic improvement. With the aim to construct an index comprising of production, reproduction and health traits of Murrah buffaloes, the production and reproduction data during a 50-year span (1971-2020) and for health traits data of 27 years (1994-2020) were analyzed. Various three, four, five, and six trait combinations of production, reproduction, and health traits were explored for construction of performance indices. The income and expenditure method was used to calculate relative economic values (REV) for traits under consideration. A total of 37 performance indices were constructed using a multi-trait combination of production, reproduction, and health traits. Out of 37 indices, the (ADMY-PY-DO-AFC-FF) based index was identified as the best, with 78%, 2%, and 20% weightage given to production, reproduction, and female fertility, respectively. Furthermore, when REVs of traits were increased by 25% and 50%, there was no change observed in the relative importance of traits in the best index, indicating that the index was robust to substantial increases in economic values. Therefore, it is recommended that the above constructed composite selection index can be employed in selection of female buffaloes to achieve sustainable genetic gain.

Is Follow-up Co-Morbidity Assessment via Laboratory Investigations in Older High Energy Trauma Patients Justified? - A Prospective-Retrospective Study

@#Introduction: The objective of the current study was to test our hypothesis that older patients sustaining high energy trauma need to be evaluated for their comorbidities similar to geriatric patients sustaining low energy trauma. Materials and methods: This study was a retrospectiveprospective analysis of 173 patients of more than 50 years of age enrolled between November 2017 and December 2018. Herewith, we have compared retrospectively collected laboratory investigations of 124 fragility fracture patients with prospectively collected laboratory investigations of 49 patients with high energy trauma. The laboratory investigations, including the liver function tests, renal function tests, indices of calcium metabolism, serum electrolytes, complete blood counts, and bone mineral density (BMD) scores. Results: Both groups were similar to each other as far as baseline demographic characteristics were concerned. The proportion of female patients and patients with nonosteoporotic range BMD (T-score >-2.5) was significantly higher in the high-energy fracture group (P value <0.05). Hypoalbuminemia (<3.4gm/dl) 17.3%, abnormalities sodium (<135mmol/L or >148mmol/L) 23.2%, Anaemia (<10g/dl) 12.7%, Hypercalcemia (>10.4mg/dl) 16.3%, Vitamin D deficiency (<20ng/ml) 17.3% are the common laboratory abnormality found in study population. No statistically significant difference was found among the two groups in terms of laboratory investigation abnormalities. Conclusion: The laboratory investigation abnormality in an older patient with a clinical fracture is independent of the mechanism of injury. The results of the current study emphasise the need for a comprehensive laboratory workup in older patients with either high- energy fractures or fragility fractures.

Neonatal outcomes following phenylephrine or norepinephrine for treatment of spinal anaesthesia-induced hypotension at emergency caesarean section in women with fetal compromise: a randomised controlled study.

BACKGROUND: Norepinephrine is as effective as phenylephrine for management of spinal anaesthesia-induced hypotension. Most of the studies comparing these vasopressors have been conducted in healthy pregnant women undergoing elective caesarean section. In the current study, we tested the null hypothesis that there is no difference in neonatal outcome when phenylephrine or norepinephrine is used to treat spinal anaesthesia-induced hypotension in women undergoing emergency caesarean section for fetal compromise. METHODS: Patients undergoing caesarean section for fetal compromise who developed spinal anaesthesia-induced hypotension were randomised to receive phenylephrine 100 µg or norepinephrine 8 µg for treatment of each hypotensive episode, defined as systolic blood pressure <100 mmHg. Umbilical cord arterial and venous blood samples were obtained for blood gas analysis. The primary outcome measure was umbilical artery pH. RESULTS: One hundred patients (50 in each group) were studied. There was no significant difference in umbilical artery pH between the two groups (mean difference 0.001; 95% CI -0.032 to 0.034). The number of hypotensive episodes, vasopressor boluses required, the incidence of bradycardia, heart rate and blood pressure trends following vasopressor administration, and the incidence of nausea/vomiting were not significantly different between groups. CONCLUSION: Phenylephrine 100 µg and norepinephrine 8 µg were not significantly different in terms of neonatal outcome when administered as intravenous boluses for treatment of spinal anaesthesia-induced hypotension in parturients undergoing emergency caesarean sections for fetal compromise.

Clinico-radiological findings of neuroendocrine tumour metastases to the orbit.

PURPOSE: We present the clinico-radiological findings of neuroendocrine tumour metastases to the orbit. METHODS: This was a multicentre, retrospective study of patients with neuroendocrine tumour metastases to the orbit. Data was collected from medical records across five different sites within Australia and the United Kingdom. RESULTS: Nine patients (eleven lesions) were identified. The most common presenting complaint was diplopia (5/9, 56%). Disease occurred bilaterally in two patients. Seven patients (78%) had extraocular muscle involvement. The lateral recti (4/9, 44%) and superior recti (2/9, 22%) were the most commonly affected. Ocular presentation preceded primary tumour diagnosis in three patients (33%). On orbital imaging, metastases were most commonly reported as well circumscribed, ovoid or round, heterogeneous, contrast-enhancing masses. Features of intralesional haemorrhage and bony invasion are uncommonly reported. CONCLUSIONS: Neuroendocrine tumour metastasis to the orbit is uncommon. Metastases have a propensity for the extraocular muscles, commonly presenting as heterogeneous, well circumscribed, contrast-enhancing lesions on neuroimaging. New ocular symptoms, a history of neuroendocrine tumours, and these radiological findings, should lead to high clinical suspicion of metastatic disease. Atypical findings warrant biopsy to exclude other causes of orbital lesions.

Outcomes in Nonagenarians with Hip Fractures Treated Conservatively and Surgically.

INTRODUCTION: We aimed to assess the clinical outcomes in nonagenarians following a hip fracture. We also further investigated the factors that influence these outcomes, such as method of treatment (operative versus conservative), co-morbidities, and pre-morbid function. MATERIALS AND METHODS: We studied 65 nonagenarians that were identifiable from our hospital hip fracture database. We reviewed various parameters of these patients admitted after sustaining a hip fracture (neck of femur or intertrochanteric) and investigated how these parameters affected patient outcomes. The main outcomes studied were: inpatient morbidity, and mortality at one year. RESULTS: Inpatient morbidity was more likely in patients with an ASA grade of 3 to 5. Urinary tract infection was the most common medical complication. The 1-year mortality was 15.4% and was significantly influenced by advancing age. Surgically managed patients had a 1-year mortality rate (14.3%) slightly less than non-operative patients (17.4%). Post injury mobility was significantly better in those who received operative treatment with 63% of surgical cases regaining ambulatory status versus 7% of conservatively managed patients. CONCLUSIONS: We presented the outcomes of hip fractures in an extreme age group in the population. In nonagenarians with hip fractures surgery was associated with a 1-year mortality rate of 14.3% which is comparable to the general hip fracture population and less than the mortality rate of conservatively managed patients (17.4%). The primary advantage of surgery would be that two-thirds of patients return to ambulatory status. This information is useful to counsel patients and their families especially since the elderly are often more fearful of surgical intervention.

Validation of Complete Hindi Version of Douleur Neuropathique 4 Questionnaire for Assessment of Neuropathic Pain.

OBJECTIVES: The Douleur Neuropathique 4 (DN4) questionnaire is a widely used tool for the diagnosis of neuropathic pain (NP). The aim was to validate the Complete Hindi version of DN4 (CH-DN4) questionnaire. MATERIALS AND METHODS: A systematic translation process was used to translate the original English DN4 into Hindi. The Hindi version was validated among patients appearing in the pain clinic of a tertiary hospital in the capital of Delhi by two different raters. We assessed the internal consistency, test-retest reliability, and inter-rater agreement, validity, sensitivity, specificity, positive and negative predictive values, and area under the curve (AUC). RESULTS: A total of 285 participants, out of which 153 had NP and 132 had non NP (NNP) were included in the study. The results showed our CH-DN4 to have good diagnostic accuracy, a score of ≥ 3.5 was found to be the best cut-off for the diagnosis of NP, with a sensitivity of 0.78, specificity of 0.76, a positive predictive value of 78.5%, and a negative predictive value of 74.5%. Cronbach's α was 0.82 (95% confidence interval: 0.80-0.84), and interclass correlation coefficients was 0.95. The AUC was >0.8 indicating excellent discrimination between NP and NNP. CONCLUSION: The CH-DN4 questionnaire has been found to be a reliable and valid screening tool with an excellent power to discriminate between NP and NNP.

Graphene Nanocoating: High Quality and Stability upon Several Stressors.

Titanium implants present 2 major drawbacks-namely, the long time needed for osseointegration and the lack of inherent antimicrobial properties. Surface modifications and coatings to improve biomaterials can lose their integrity and biological potential when exposed to stressful microenvironments. Graphene nanocoating (GN) can be deposited onto actual-size dental and orthopedic implants. It has antiadhesive properties and can enhance bone formation in vivo. However, its ability to maintain structural integrity and quality when challenged by biologically relevant stresses remains largely unknown. GN was produced by chemical vapor deposition and transferred to titanium via a polymer-assisted transfer technique. GN has high inertness and did not increase expression of inflammatory markers by macrophages, even in the presence of lipopolysaccharides. It kept high coverage at the top tercile of tapered dental implant collars after installation and removal from bone substitute and pig maxilla. It also resisted microbiologically influenced corrosion, and it maintained very high coverage area and quality after prolonged exposure to biofilms and their removal by different techniques. Our findings show that GN is unresponsive to harsh and inflammatory environments and that it maintains a promising level of structural integrity on the top tercile of dental implant collars, which is the area highly affected by biofilms during the onset of implant diseases. Our findings open the avenues for the clinical studies required for the use of GN in the development of implants that have higher osteogenic potential and are less prone to implant diseases.