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This paper describes a computational investigation of multimode instability growth and multimaterial mixing induced by multiple shock waves in a high-energy-density (HED) environment, where pressures exceed 1 Mbar. The simulations are based on a series of experiments performed at the National Ignition Facility (NIF) and designed as an HED analogue of non-HED shock-tube studies of the Richtmyer–Meshkov instability and turbulent mixing. A three-dimensional computational modelling framework is presented. It treats many complications absent from canonical non-HED shock-tube flows, including distinct ion and free-electron internal energies, non-ideal equations of state, radiation transport and plasma-state mass diffusivities, viscosities and thermal conductivities. The simulations are tuned to the available NIF data, and traditional statistical quantities of turbulence are analysed. Integrated measures of turbulent kinetic energy and enstrophy both increase by over an order of magnitude due to reshock. Large contributions to enstrophy production during reshock are seen from both the baroclinic source and enstrophy–dilatation terms, highlighting the significance of fluid compressibility in the HED regime. Dimensional analysis reveals that Reynolds numbers and diffusive Péclet numbers in the HED flow are similar to those in a canonical non-HED analogue, but conductive Péclet numbers are much smaller in the HED flow due to efficient thermal conduction by free electrons. It is shown that the mechanism of electron thermal conduction significantly softens local spanwise gradients of both temperature and density, which causes a minor but non-negligible decrease in enstrophy production and small-scale mixing relative to a flow without this mechanism.
Bipolar disorder is associated with premature mortality, but evidence is mostly derived from Western countries. There has been no research evaluating shortened lifespan in bipolar disorder using life-years lost (LYLs), which is a recently developed mortality metric taking into account illness onset for life expectancy estimation. The current study aimed to examine the extent of premature mortality in bipolar disorder patients relative to the general population in Hong Kong (HK) in terms of standardised mortality ratio (SMR) and excess LYLs, and changes of mortality rate over time.
This population-based cohort study investigated excess mortality in 12 556 bipolar disorder patients between 2008 and 2018, by estimating all-cause and cause-specific SMRs, and LYLs. Trends in annual SMRs over the 11-year study period were assessed. Study data were retrieved from a territory-wide medical-record database of HK public healthcare services.
Patients had higher all-cause [SMR: 2.60 (95% CI: 2.45–2.76)], natural-cause [SMR: 1.90 (95% CI: 1.76–2.05)] and unnatural-cause [SMR: 8.63 (95% CI: 7.34–10.03)] mortality rates than the general population. Respiratory diseases, cardiovascular diseases and cancers accounted for the majority of deaths. Men and women with bipolar disorder had 6.78 (95% CI: 6.00–7.84) years and 7.35 (95% CI: 6.75–8.06) years of excess LYLs, respectively. The overall mortality gap remained similar over time, albeit slightly improved in men with bipolar disorder.
Bipolar disorder is associated with increased premature mortality and substantially reduced lifespan in a predominantly Chinese population, with excess deaths mainly attributed to natural causes. Persistent mortality gap underscores an urgent need for targeted interventions to improve physical health of patients with bipolar disorder.
To conduct a pilot study implementing combined genomic and epidemiologic surveillance for hospital-acquired multidrug-resistant organisms (MDROs) to predict transmission between patients and to estimate the local burden of MDRO transmission.
Pilot prospective multicenter surveillance study.
The study was conducted in 8 university hospitals (2,800 beds total) in Melbourne, Australia (population 4.8 million), including 4 acute-care, 1 specialist cancer care, and 3 subacute-care hospitals.
All clinical and screening isolates from hospital inpatients (April 24 to June 18, 2017) were collected for 6 MDROs: vanA VRE, MRSA, ESBL Escherichia coli (ESBL-Ec) and Klebsiella pneumoniae (ESBL-Kp), and carbapenem-resistant Pseudomonas aeruginosa (CRPa) and Acinetobacter baumannii (CRAb). Isolates were analyzed and reported as routine by hospital laboratories, underwent whole-genome sequencing at the central laboratory, and were analyzed using open-source bioinformatic tools. MDRO burden and transmission were assessed using combined genomic and epidemiologic data.
In total, 408 isolates were collected from 358 patients; 47.5% were screening isolates. ESBL-Ec was most common (52.5%), then MRSA (21.6%), vanA VRE (15.7%), and ESBL-Kp (7.6%). Most MDROs (88.3%) were isolated from patients with recent healthcare exposure.
Combining genomics and epidemiology identified that at least 27.1% of MDROs were likely acquired in a hospital; most of these transmission events would not have been detected without genomics. The highest proportion of transmission occurred with vanA VRE (88.4% of patients).
Genomic and epidemiologic data from multiple institutions can feasibly be combined prospectively, providing substantial insights into the burden and distribution of MDROs, including in-hospital transmission. This analysis enables infection control teams to target interventions more effectively.
Background: Detection of unusual carbapenemase-producing organisms (CPOs) in a healthcare facility may signify broader regional spread. During investigation of a VIM-producing Pseudomonas aeruginosa (VIM-CRPA) outbreak in a long-term acute-care hospital in central Florida, enhanced surveillance identified VIM-CRPA from multiple facilities, denoting potential regional emergence. We evaluated infection control and performed screening for CPOs in skilled nursing facilities (SNFs) across the region to identify potential CPO reservoirs and improve practices. Methods: All SNFs in 2 central Florida counties were offered a facility-wide point-prevalence survey (PPS) for CPOs and a nonregulatory infection control consultation. PPSs were conducted using a PCR-based screening method; specimens with a carbapenemase gene detected were cultured to identify the organisms. Infection control assessments focused on direct observations of hand hygiene (HH), environmental cleaning, and the sink splash zone. Thoroughness of environmental cleaning was evaluated using fluorescent markers applied to 6 standardized high-touch surfaces in at least 2 rooms per facility. Results: Overall, 21 (48%) SNFs in the 2-county region participated; 18 conducted PPS. Bed size ranged from 40 to 391, 5 (24%) facilities were ventilator-capable SNFs (vSNFs), and 12 had short-stay inpatient rehabilitation units. Of 1,338 residents approached, 649 agreed to rectal screening, and 14 (2.2%) carried CPOs. CPO-colonized residents were from the ventilator-capable units of 3 vSNFs (KPC-CRE=7; KPC-CRPA=1) and from short-stay units of 2 additional facilities (VIM-CRPA, n = 5; KPC-CRE, n = 1). Among the 5 facilities where CPO colonization was identified, the prevalence ranged from 1.1% in a short-stay unit to 16.1% in a ventilator unit. All facilities had access to soap and water in resident bathrooms; 14 (67%) had alcohol-based hand rubs accessible. Overall, mean facility HH adherence was 52% (range, 37%–66%; mean observations per facility = 106) (Fig. 1). We observed the use of non–EPA-registered disinfectants and cross contamination from dirty to clean areas during environmental cleaning; the overall surface cleaning rate was 46% (n = 178 rooms); only 1 room had all 6 markers removed. Resident supplies were frequently stored in the sink splash zone. Conclusions: A regional assessment conducted in response to emergence of VIM-CRPA identified a relatively low CPO prevalence at participating SNFs; CPOs were primarily identified in vSNFs and among short-stay residents. Across facilities, we observed low adherence to core infection control practices that could facilitate spread of CPOs and other resistant organisms. In this region, targeting ventilator and short-stay units of SNFs for surveillance and infection control efforts may have the greatest prevention impact.
As the novel coronavirus disease 2019 changed patient presentation, this study aimed to prospectively identify these changes in a single ENT centre.
A seven-week prospective case series was conducted of urgently referred patients from primary care and accident and emergency department.
There was a total of 133 referrals. Referral rates fell by 93 per cent over seven weeks, from a mean of 5.4 to 0.4 per day. Reductions were seen in referrals from both primary care (89 per cent) and the accident and emergency department (93 per cent). Presentations of otitis externa and epistaxis fell by 83 per cent, and presentations of glandular fever, tonsillitis and peritonsillar abscess fell by 67 per cent.
Coronavirus disease 2019 has greatly reduced the number of referrals into secondary care ENT. The cause for this reduction is likely to be due to patients’ increased perceived risk of the virus presence in a medical setting. The impact of this reduction is yet to be ascertained, but will likely result in a substantial increase in emergency pressures once the lockdown is lifted and the general public's perception of the coronavirus disease 2019 risk reduces.
Introduction: There are few large-scale studies assessing the true risk of epinephrine use during anaphylaxis in adults. We aimed to assess the demographics, clinical characteristics, and secondary effects of epinephrine treatment and to determine factors associated with major and minor secondary effects associated with epinephrine use among adults with anaphylaxis. Methods: From May 2012 to February 2018, adults presenting to the Hôpital du Sacré-Coeur de Montréal (HSCM) emergency department (ED) with anaphylaxis were recruited prospectively as part of the Cross-Canada Anaphylaxis Registry (C-CARE). Missed cases were identified through a previously validated algorithm. Data were collected on demographics, clinical characteristics, and management of anaphylaxis using a structured chart review. Multivariate logistic regression models were compared to estimate factors associated with side effects of epinephrine administration. Results: Over a 6-year period, 402 adult patients presented to the ED at HSCM with anaphylaxis. The median age was 38 years (Interquartile Range [IQR]: 27, 52) and 40.4% were males. The main trigger for anaphylaxis was food (53.0%). A total of 286 patients (71.1%) received epinephrine treatment, of which 23.9% were treated in the pre-hospital setting, 47.0% received treatment in the ED, and 5.0% received epinephrine in both settings. Among patients treated with epinephrine, major secondary effects were rare (1.4% of patients), including new changes to electrocardiogram, arrhythmia, and neurological symptoms. Minor secondary effects due to epinephrine were reported in 50.0% of patients, mainly inappropriate sinus tachycardia (defined as a rate over 100 beats/minute in 30.1%). Major cardiovascular secondary effects were associated with regular use of beta-blockers (aOR 1.10 [95%CI, 1.02, 1.18]), regular use of ACE-inhibitors (aOR 1.16 [95%CI, 1.07, 1.27]), and receiving more than two doses of epinephrine (aOR 1.09 [95%CI, 1.00, 1.18]). The model was adjusted for age, history of ischemic heart disease, trigger of anaphylaxis, presence of asthma, sex, and reaction severity. Inappropriate sinus tachycardia was more likely in females (aOR 1.18 [95%CI, 1.04, 1.33]) and palpitations, tremors, and psychomotor agitation were more likely in females (aOR 1.09 [95%CI, 1.00, 1.19]) and among those receiving more than two doses of epinephrine (aOR 1.49 [95%CI, 1.14, 1.96]). The models were adjusted for age, regular use of medications, history of ischemic heart disease, triggers of anaphylaxis, presence of asthma, reaction severity, and IV administration of epinephrine. Conclusion: The low rate of occurrence of major secondary effects of epinephrine in the treatment of anaphylaxis in our study demonstrates the overall safety of epinephrine use.
Introduction: Time-to-treatment plays a pivotal role in survival from sudden cardiac arrest (SCA). Every minute delay in defibrillation results in a 7-10% reduction in survival. This is particularly problematic in rural and remote regions, where bystander and EMS response is often prolonged and automated external defibrillators (AED) are often not available. Our objective was to examine the feasibility of a novel AED drone delivery method for rural and remote SCA. A secondary objective was to compare times between AED drone delivery and ambulance response to various mock SCA resuscitations. Methods: We conducted 6 simulations in two different rural communities in southern Ontario. During phase 1 (4 simulations) a “mock” call was placed to 911 and a single AED drone and an ambulance were simultaneously dispatched from the same location to a pre-determined destination. Once on scene, trained first responders retrieved the AED from the drone and initiated resuscitative efforts on a manikin. The second phase (2 scenarios) were done in a similar manner save for the drone being dispatched from a regionally optimized location for drone response. Results: Phase 1: The distance from dispatch location to scene varied from 6.6 km to 8.8 km. Mean (SD) response time from 911 call to scene arrival was 11.2 (+/- 1.0) minutes for EMS compared to 8.1 (+/- 0.1) for AED drone delivery. In all four simulations, the AED drone arrived before EMS, ranging from 2.1 to 4.4 minutes faster. The mean time for trained responders to retrieve the AED and apply it to the manikin was 35 (+/- 5) sec. No difficulties were encountered in drone activation by dispatch, drone lift off, landing or removal of the AED from the drone by responders. Phase 2: The ambulance response distance was 20km compared to 9km for the drone. Drones were faster to arrival at the scene by 7 minutes and 8 minutes with AED application 6 and 7 minutes prior to ambulance respectively. Conclusion: This implementation study suggests AED drone delivery is feasible with improvements in response time during a simulated SCA scenario. These results suggest the potential for AED drone delivery to decrease time to first defibrillation in rural and remote communities. Further research is required to determine the appropriate distance for drone delivery of an AED in an integrated EMS system as well as optimal strategies to simplify bystander application of a drone delivered AED.
The risk factors of criminal behavior in patients with schizophrenia are not well explored. This study is to explore the risk factors for criminal behavior in patients with schizophrenia in rural China.
We used data from a 14-year prospective follow-up study (1994-2008) of criminal behavior among a cohort (n=510) of patients with schizophrenia in Xinjin County, Chengdu, China.
There were 489 patients (95.9%) who were followed up from 1994 to 2008. The rate of criminal behavior was 13.5% among these patients with schizophrenia during the follow-up period. Compared with female subjects (6 cases, 20.0%), male patients had significantly higher rate of violent criminal behavior (e.g., arson, sexual assault, physical assault, and murder) (24 cases, 80.0%) (p< 0.001). Bivariate analyses showed that the risk of criminal behavior was significantly associated with being unmarried, of younger age, previous violent behavior, homelessness, lower family economic status, no family caregivers, and higher scores on measures (PANSS) of positive, negative, and total symptoms of illness. In multiple logistic regression analyses being unmarried and previous violent behavior were identified as independent predictors of increased criminal behavior in persons with schizophrenia.
The risk factors for criminal behavior among patients with schizophrenia should be understood within a particular social context. Criminal behavior may be predicted by specific characteristics of patients with schizophrenia in rural community. The findings of risk factors for criminal behavior should be considered in planning community mental health care and interventions for high-risk patients and their families.
Currently there is no consensus regarding how long anti-psychotics medication should be continued following a first/single psychotic episode. Clinically patients often request discontinuation after a period of remission. This is one of the first double-blind randomized-controlled studies designed to address the issue.
Patients with DSM-IV schizophrenia and related psychoses (excluding substance induced psychosis) who remitted well following a first/single-episode, and had remained well on maintenance medication for one year, were randomized to receive either maintenance therapy with quetiapine (400 mg/day), or placebo for 12 months. Relapse was defined by the presence of (i) an increase in at least one of the following PANSS psychotic symptom items to a threshold score (delusion, hallucinatory behaviour, conceptual disorganization, unusual thought content, suspiciousness); (ii) CGI Severity of Illness 3 or above; and (iii) CGI Improvement 5 or above.
178 patients were randomized. 144 patients completed the study (80.9%). The relapse rate was 33.7% (30/89) for the maintenance group and 66.3% (59/89) for the placebo group (log-rank test, chi-square=13.328, p<0.001). Relapse was not related to age or gender. Other significant predictors of relapse include medication status, pre-morbid schizotypal traits, verbal memory and soft neurological signs.
There is a substantial risk of relapse if medication is discontinued in remitted first-episode psychosis patients following one year of maintenance therapy. On the contrary 33.7% of patients discontinued medication and remained well.
Medication discontinuation in remitted single episode patients after a period of maintenance therapy is a major clinical decision and thus the identification of risk factors controlling for medication status is important.
Following a first/single episode with DSM-IV schizophrenia and related psychoses, remitted patients who had remained well on maintenance medication for at least one year were randomized to receive either maintenance therapy (with quetiapine 400 mg/day), or placebo for 12 months.
178 patients were randomized. Relapse rates were 33.7% (30/89) in maintenance group and 66.3% (59/89) in placebo group. Potential predictors were initially identified in univariate Cox regression models (p<0.1) and were subsequently entered into a multivariate Cox regression model for measuring the relapse risk. Significant predictors included patients on placebo (hazard ratio, 0.41; CI, 0.25 – 0.68; p=0.001); having more pre-morbid schizotypal traits (hazard ratio, 2.32; CI, 1.33 – 4.04; p=0.003); scoring lower in the logical memory test (hazard ratio, 0.94; CI, 0.9 – 0.99; p=0.028); and having more soft neurological signs (disinhibition) (hazard ratio, 1.33; CI, 1.02 – 1.74; p=0.039).
Relapse predictors may help to inform clinical decisions about discontinuation of maintenance therapy specifically for patients with a first/single episode psychosis following at least one year of maintenance therapy.
We are grateful to Dr TJ Yao at the Clinical Trials Center, University of Hong Kong, for statistical advice. The study was supported by investigator initiated trial award from AstraZeneca and the Research Grants Council Hong Kong (Project number: 765505).
Social anxiety disorder (SAD) is a strong risk factor for the development of depressive disorders (major depressive disorder or dysthymia).
Identification of blood-based molecular predictors of a subsequent depressive episode in SAD.
Objectives: To screen SAD patient serum for biomarkers which predict the onset of depressive disorders over a 2-year follow-up period.
Multiplexed-immunoassay data obtained from 143 SAD patients without co-morbid depressive disorders, recruited within the Netherlands Study of Depression and Anxiety (NESDA), were investigated. The serum screen included 165 mainly immunological, metabolical and hormonal analytes. Predictive performance of identified biomarkers and clinical variables (e.g. Beck Anxiety Inventory) was assessed using receiver operating characteristics curves (ROC) and represented by the area under the ROC curve (AUC). Stepwise logistic regression was used to select an optimal set of patient parameters, combining predictive serum analytes and clinical variables.
A set of four serum analytes and four associated clinical variables reached an AUC of 0.86 for the identification of SAD individuals, who developed a subsequent depressive episode. Throughout our analyses, biomarker panels yielded superior discriminative performance compared to clinical variables alone.
We report the discovery of a serum marker panel with good predictive performance to identify SAD individuals prone to develop depressive disorders in a naturalistic cohort design. Furthermore, we emphasise the importance to combine biological markers and clinical parameters for disease course predictions in psychiatry. Validated biomarkers could help to identify SAD patients at risk of a depressive episode, thus facilitating early treatment and improving clinical outcome.
Studies have shown that mental health problems during pregnancy have adverse effects on fetal growth. The impact of depressive and anxiety symptoms during pregnancy on the fetus have not yet been examined in Singapore.
To examine the association between mental health problems during the second trimester of pregnancy on the quality of the pregnancy, reflected by birth weight and birth length of the newborn.
This study aims to understand the importance of mental health during pregnancy on the development of the child in an Asian population.
Preliminary data of a prospective cohort study of pregnant women (GUSTO), were followed from pregnancy onwards. At 26 weeks of the pregnancy, the Edinburgh Postnatal Depression Scale (EPDS), the Beck Depression Inventory (BDI) and the State Trait Anxiety Inventory (STAI) were administered. Data on birth parameters were collected from medical records.
Linear regression analyses of preliminary data show negative correlations between depressive symptoms measured with EPDS (n = 1025, P = 0.54), BDI (n = 1012, P = 0.001), and anxiety symptoms measured with STAI (n = 1023, P = 0.002) and birth length (corrected for gestational age and gender). No associations were found for birth weight.
There is an association between depressive and anxiety symptoms reported at the end of the second trimester of the pregnancy and birth length, but not birth weight, of the newborn. As it is known that fetal length increases mainly in the second trimester, it suggests that stress of the mother influences the development of the fetus during this trimester.
The national implementation of competency-based medical education (CBME) has prompted an increased interest in identifying and tracking clinical and educational outcomes for emergency medicine training programs. For the 2019 Canadian Association of Emergency Physicians (CAEP) Academic Symposium, we developed recommendations for measuring outcomes in emergency medicine training in the context of CBME to assist educational leaders and systems designers in program evaluation.
We conducted a three-phase study to generate educational and clinical outcomes for emergency medicine (EM) education in Canada. First, we elicited expert and community perspectives on the best educational and clinical outcomes through a structured consultation process using a targeted online survey. We then qualitatively analyzed these responses to generate a list of suggested outcomes. Last, we presented these outcomes to a diverse assembly of educators, trainees, and clinicians at the CAEP Academic Symposium for feedback and endorsement through a voting process.
Academic Symposium attendees endorsed the measurement and linkage of CBME educational and clinical outcomes. Twenty-five outcomes (15 educational, 10 clinical) were derived from the qualitative analysis of the survey results and the most important short- and long-term outcomes (both educational and clinical) were identified. These outcomes can be used to help measure the impact of CBME on the practice of Emergency Medicine in Canada to ensure that it meets both trainee and patient needs.
Studies suggest that alcohol consumption and alcohol use disorders have distinct genetic backgrounds.
We examined whether polygenic risk scores (PRS) for consumption and problem subscales of the Alcohol Use Disorders Identification Test (AUDIT-C, AUDIT-P) in the UK Biobank (UKB; N = 121 630) correlate with alcohol outcomes in four independent samples: an ascertained cohort, the Collaborative Study on the Genetics of Alcoholism (COGA; N = 6850), and population-based cohorts: Avon Longitudinal Study of Parents and Children (ALSPAC; N = 5911), Generation Scotland (GS; N = 17 461), and an independent subset of UKB (N = 245 947). Regression models and survival analyses tested whether the PRS were associated with the alcohol-related outcomes.
In COGA, AUDIT-P PRS was associated with alcohol dependence, AUD symptom count, maximum drinks (R2 = 0.47–0.68%, p = 2.0 × 10−8–1.0 × 10−10), and increased likelihood of onset of alcohol dependence (hazard ratio = 1.15, p = 4.7 × 10−8); AUDIT-C PRS was not an independent predictor of any phenotype. In ALSPAC, the AUDIT-C PRS was associated with alcohol dependence (R2 = 0.96%, p = 4.8 × 10−6). In GS, AUDIT-C PRS was a better predictor of weekly alcohol use (R2 = 0.27%, p = 5.5 × 10−11), while AUDIT-P PRS was more associated with problem drinking (R2 = 0.40%, p = 9.0 × 10−7). Lastly, AUDIT-P PRS was associated with ICD-based alcohol-related disorders in the UKB subset (R2 = 0.18%, p < 2.0 × 10−16).
AUDIT-P PRS was associated with a range of alcohol-related phenotypes across population-based and ascertained cohorts, while AUDIT-C PRS showed less utility in the ascertained cohort. We show that AUDIT-P is genetically correlated with both use and misuse and demonstrate the influence of ascertainment schemes on PRS analyses.
This study aimed to highlight the key studies that have led to the current understanding and treatment of head and neck cancer.
The Thomson Reuters Web of Science database was used to identify relevant manuscripts. The results were ranked according to the number of citations. The 100 most cited papers were analysed.
A total of 63 538 eligible papers were returned. The median number of citations was 626. The most cited paper compared radiotherapy with and without cetuximab (3205 citations). The New England Journal of Medicine had the most citations (23 514), and the USA had the greatest number of publications (n = 66). The most common topics of publication were the treatment (n = 45) and basic science (n = 19) of head and neck cancer, followed by the role of human papillomavirus (n = 16).
This analysis highlighted key articles that influenced head and neck cancer research and treatment. It serves as a guide as to what makes a ‘citable’ paper in this field.
Abnormal effort-based decision-making represents a potential mechanism underlying motivational deficits (amotivation) in psychotic disorders. Previous research identified effort allocation impairment in chronic schizophrenia and focused mostly on physical effort modality. No study has investigated cognitive effort allocation in first-episode psychosis (FEP).
Cognitive effort allocation was examined in 40 FEP patients and 44 demographically-matched healthy controls, using Cognitive Effort-Discounting (COGED) paradigm which quantified participants’ willingness to expend cognitive effort in terms of explicit, continuous discounting of monetary rewards based on parametrically-varied cognitive demands (levels N of N-back task). Relationship between reward-discounting and amotivation was investigated. Group differences in reward-magnitude and effort-cost sensitivity, and differential associations of these sensitivity indices with amotivation were explored.
Patients displayed significantly greater reward-discounting than controls. In particular, such discounting was most pronounced in patients with high levels of amotivation even when N-back performance and reward base amount were taken into consideration. Moreover, patients exhibited reduced reward-benefit sensitivity and effort-cost sensitivity relative to controls, and that decreased sensitivity to reward-benefit but not effort-cost was correlated with diminished motivation. Reward-discounting and sensitivity indices were generally unrelated to other symptom dimensions, antipsychotic dose and cognitive deficits.
This study provides the first evidence of cognitive effort-based decision-making impairment in FEP, and indicates that decreased effort expenditure is associated with amotivation. Our findings further suggest that abnormal effort allocation and amotivation might primarily be related to blunted reward valuation. Prospective research is required to clarify the utility of effort-based measures in predicting amotivation and functional outcome in FEP.
Better understanding of interplay among symptoms, cognition and functioning in first-episode psychosis (FEP) is crucial to promoting functional recovery. Network analysis is a promising data-driven approach to elucidating complex interactions among psychopathological variables in psychosis, but has not been applied in FEP.
This study employed network analysis to examine inter-relationships among a wide array of variables encompassing psychopathology, premorbid and onset characteristics, cognition, subjective quality-of-life and psychosocial functioning in 323 adult FEP patients in Hong Kong. Graphical Least Absolute Shrinkage and Selection Operator (LASSO) combined with extended Bayesian information criterion (BIC) model selection was used for network construction. Importance of individual nodes in a generated network was quantified by centrality analyses.
Our results showed that amotivation played the most central role and had the strongest associations with other variables in the network, as indexed by node strength. Amotivation and diminished expression displayed differential relationships with other nodes, supporting the validity of two-factor negative symptom structure. Psychosocial functioning was most strongly connected with amotivation and was weakly linked to several other variables. Within cognitive domain, digit span demonstrated the highest centrality and was connected with most of the other cognitive variables. Exploratory analysis revealed no significant gender differences in network structure and global strength.
Our results suggest the pivotal role of amotivation in psychopathology network of FEP and indicate its critical association with psychosocial functioning. Further research is required to verify the clinical significance of diminished motivation on functional outcome in the early course of psychotic illness.
Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9.
We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.
16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (−0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01).
PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.