To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Clozapine is generally considered as the treatment of choice for patients with treatment-resistant schizophrenia (TRS). However, its superiority has recently been questioned because olanzapine has been suggested as non-inferior to clozapine in its effectiveness.
We aimed to investigate the current status of clozapine prescriptions to identify any disparity between clinical guidelines and real-world practices.
In this study, we utilised the Health Insurance Review Agency database in the Republic of Korea to investigate the real-world effectiveness of clozapine for patients with TRS. We compared differences in patient variables before and after clozapine administration, and we also performed survival analyses for both psychiatric admissions and emergency room visits among patients who used clozapine or olanzapine.
This study investigated an incident cohort of 64 442 patients, and 2338 patients have been prescribed clozapine. Of these, 998 patients had TRS. In survival analysis, clozapine showed a worse survival rate for psychiatric admissions than olanzapine (hazard ratio 0.615). We also identified that clinicians tended to try a number of antipsychotics, as recommended, before starting patients on clozapine.
In conclusion, we found that olanzapine led to higher survival rates for psychiatric admissions than clozapine. Thus, considering the risk of serious adverse effects, clozapine may be used conservatively. Considering several studies advocating superior efficacy of clozapine, further studies with extensive data are recommended.
Current evidence on antipsychotic treatment and risk of psychiatric hospitalization in first-episode schizophrenia (FES) is largely based on the findings from randomized clinical trials (RCTs). However, the generalization of the findings to real-world patients is limited due to inherent caveats of the RCT. We aimed to investigate the treatment discontinuation and risk of psychiatric hospitalization using a nationwide population database.
The Health Insurance Review Agency database in South Korea was obtained, and the observation period started from 1 January 2009 to 31 December 2016. We defined the maintenance period as the period from 6-month after the diagnosis of schizophrenia, which is utilized for the main results. For a total of 44 396 patients with FES, a within-individual Cox regression model was used to compare the risk of the treatment discontinuation and psychiatric hospitalization.
In group comparison, a long-acting injectable (LAI) antipsychotic group was associated with the lowest risk of the treatment discontinuation (0.64, 0.55–0.75) and psychiatric hospitalization (0.29, 0.22–0.38) in comparison with a typical antipsychotic group and no use, respectively. Among individual antipsychotics, the lowest risk of the treatment discontinuation was observed in LAI paliperidone (0.46, 0.37–0.66) compared to olanzapine. Clozapine was found to be the most effective antipsychotic in lowering the risk of psychiatric hospitalization as monotherapy compared to no use (0.23, 0.18–0.31).
In real-world patients with FES, LAI paliperidone and clozapine were associated with low treatment discontinuation and better effectiveness in lowering the risk of psychiatric hospitalization.
It has been reported that the follower in a tandem configuration with no wall (0W) reduces the time-averaged input power by utilizing the vortex interception mode (Zhu et al., Phys. Rev. Lett., vol. 113, 2014, p. 238105). In the present study, a numerical simulation is conducted with two self-propelled flexible fins in the tandem configuration near a single wall (1W) and two parallel walls (2W). Contrary to the vortex interception for 0W, the follower employs spontaneously a mixed mode (i.e. a combination of the vortex interception mode and the slalom mode) for 1W and the slalom mode for 2W. Although the lateral motion of the follower for 0W, 1W and 2W is synchronized with the induced lateral flow generated by the leader, the time-averaged input power of the follower for 1W and 2W is reduced significantly due to the enhanced lateral flow by the vortex–vortex interaction near the wall. The jet-like flow opposite to the moving direction continuously hinders the movement of the follower for 0W, whereas the follower for 1W and 2W utilizes the negative horizontal flow when passing between the main vortex and the induced vortex near the wall, leading to a decrease of the thrust force acting on the follower allowing the follower to keep pace with the leader. The global efficiency of the schooling fins is optimized with a small heaving amplitude of the follower and a critical value of phase difference between the leader and follower when the values of the wall proximity and bending rigidity are moderate.
Network approach has been applied to a wide variety of psychiatric disorders. The aim of the present study was to identify network structures of remitters and non-remitters in patients with first-episode psychosis (FEP) at baseline and the 6-month follow-up.
Participants (n = 252) from the Korean Early Psychosis Study (KEPS) were enrolled. They were classified as remitters or non-remitters using Andreasen's criteria. We estimated network structure with 10 symptoms (three symptoms from the Positive and Negative Syndrome Scale, one depressive symptom, and six symptoms related to schema and rumination) as nodes using a Gaussian graphical model. Global and local network metrics were compared within and between the networks over time.
Global network metrics did not differ between the remitters and non-remitters at baseline or 6 months. However, the network structure and nodal strengths associated with positive-self and positive-others scores changed significantly in the remitters over time. Unique central symptoms for remitters and non-remitters were cognitive brooding and negative-self, respectively. The correlation stability coefficients for nodal strength were within the acceptable range.
Our findings indicate that network structure and some nodal strengths were more flexible in remitters. Negative-self could be an important target for therapeutic intervention.
Background: After the Middle East respiratory syndrome coronavirus outbreak in Korea in 2015, the government newly established the additional reimbursement for infection prevention to encourage infection control activities in the hospitals. The new policy was announced in December 2015 and was implemented in September 2016. We evaluated how infection control activities improved in hospitals after the change of government policy in Korea. Methods: Three cross-sectional surveys using the WHO Hand Hygiene Self-Assessment Framework (HHSAF) were conducted in 2013, 2015, and 2017. Using multivariable linear regression model including hospital characteristics, we analyzed the changes in total HHSAF scores according to the survey time. Results: In total, 32 hospitals participated in the survey in 2013, 52 in 2015, and 101 in 2017. The number of inpatient beds per infection control professionals decreased from 324 in 2013 to 303 in 2015 and 179 in 2017. Most hospitals were at intermediate or advanced levels of progress (90.6% in 2013, 86.6% in 2015, and 94.1% in 2017). In a multivariable linear regression model, the total HHSAF scores were significantly associated with hospital teaching status (β coefficient of major teaching hospital, 52.6; 95% CI, 8.9–96.4; P = .018), bed size (β coefficient of 100-bed increase, 5.1; 95% CI, 0.3–9.8; P = .038), and survey time (β coefficient of 2017 survey, 45.1; 95% CI, 19.3–70.9; P = .001). Conclusions: After the national policy implementation, the number of infection control professionals increased, and the promotion of hand hygiene activities was strengthened in Korean hospitals.
Background: Recently, healthcare-associated infections (HAIs) in long-term care hospitals (LTCHs) have markedly increased, but no infection control policy has been established in South Korea. We investigated the current HAI surveillance system and executed a point-prevalence pilot study in LTCHs. Methods: HAIs were defined by newly established surveillance manual based on McGeer criteria revised in 2012. Three LTCHs in Seoul and Gyeonggi province were voluntarily recruited, and data were collected from up to 50 patients who were hospitalized on August 1. The medical records from September to November 2018 were retrospectively reviewed by a charge nurse for infection control per each hospitals after 1 day of training specific for LTCH surveillance. All data were reviewed by a senior researcher visiting onsite. Results: The participating hospitals had 272.33 ± 111.01 beds. Only 1 hospital had an onsite microbiological laboratory. In total, 156 patients were enrolled and 5 HAIs were detected, for a prevalence rate of 3.2%. The average patient age was 79.04 ± 9.92 years. The HAIs included 2 urinary tract infections, skin and soft-tissue infection, low respiratory infection, and conjunctivitis. Conclusions: This is the first survey of HAI in LTCHs in South Korea. The 3.2% prevalence rate is lower than those from previous reports from the European Union or the United States. This study supports the development of a national HAI surveillance and infection control system in LTCHs, although implementation may be limited due to the lack of laboratory support and infection control infrastructure in Korea.
To investigate the impacts of depression screening, diagnosis and treatment on major adverse cardiac events (MACEs) in acute coronary syndrome (ACS).
Prospective cohort study including a nested 24-week randomised clinical trial for treating depression was performed with 5–12 years after the index ACS. A total of 1152 patients recently hospitalised with ACS were recruited from 2006 to 2012, and were divided by depression screening and diagnosis at baseline and 24-week treatment allocation into five groups: 651 screening negative (N), 55 screening positive but no depressive disorder (S), 149 depressive disorder randomised to escitalopram (E), 151 depressive disorder randomised to placebo (P) and 146 depressive disorder receiving medical treatment only (M).
Cumulative MACE incidences over a median 8.4-year follow-up period were 29.6% in N, 43.6% in S, 40.9% in E, 53.6% in P and 59.6% in M. Compared to N, screening positive was associated with higher incidence of MACE [adjusted hazards ratio 2.15 (95% confidence interval 1.63–2.83)]. No differences were found between screening positive with and without a formal depressive disorder diagnosis. Of those screening positive, E was associated with a lower incidence of MACE than P and M. M had the worst outcomes even compared to P, despite significantly milder depressive symptoms at baseline.
Routine depression screening in patients with recent ACS and subsequent appropriate treatment of depression could improve long-term cardiac outcomes.
Mycoplasma pneumoniae is a main pathogen causing community-acquired pneumonia in children and young adults. Since the emergence of macrolide-resistant M. pneumoniae in the early 2000s in Japan, it has been increasingly reported worldwide as a growing problem in treatment for children. With increasing macrolide-resistant M. pneumoniae and limited data regarding its characterization and molecular analysis, we investigated the dominant M. pneumoniae strains during the recent outbreak in South Korea, and evaluated if there was an association between a specific type and macrolide resistance. Between October 2014 and December 2016 in South Korea, 249 respiratory specimens obtained from patients with confirmed M. pneumoniae pneumonia were genotyped the P1 adhesin gene, and the mutations associated with resistance (A2063G and A2064G) were tested by sequencing the targeted domain V regions of the 23S ribosomal RNA gene. Results revealed that M. pneumoniae type 1 were predominant, which was strongly associated with macrolide-resistance during the whole study period. This is the first study assessing whether M. pneumoniae subtype is related to macrolide resistance during the outbreak of M. pneumoniae.
In the Republic of Korea, despite the introduction of one-dose universal varicella vaccination in 2005 and achieving a high coverage rate of 98.9% in 2012, the incidence rate has been increased sevenfold. This study aimed to investigate time trends of varicella incidence rate, assessing the age, period and birth cohort effects. We used national data on the annual number of reported cases from 2006 to 2017. A log-linear Poisson regression model was used to estimate age–period–cohort effects on varicella incidence rate. From 2006 to 2017, the incidence of varicella increased from 22.5 cases to more than 154.8 cases per 100 000. Peak incidence has shifted from 4 to 6 years old. The estimated period and cohort effects showed significant upward patterns, with a linear increasing trend by net drift. There has been an increase in the incidence among the Korean population regarding period and cohort despite the universal vaccination of varicella vaccine. Our data suggest the need for additional studies to address the current gap in herd immunity.
Traumatic brain injury (TBI) is an important public health concern because of the high mortality rate of young people and a high proportion among the trauma. According to studies, patients visiting the emergency department (ED) with TBI comprise 1.4% of all ED patients.
The authors think that the characteristics of patients with TBI will vary according to the age group. Therefore, the purpose of this study is to investigate the clinical and social characteristics of patients with TBI visiting the ED by age group.
Trauma patients who conducted brain CT at the ED of Korean University Hospital (three hospitals) for 3 years from March 2013 to February 2016 were enrolled. Medical records were investigated retrospectively. The GCS scores were estimated at initial ED arrival. The primary outcome was to determine the characteristics of each age groups with gender, severity (by GSC score), trauma mechanism, and admission rate.
A total of 15,567 TBI patients received brain CT evaluation during the investigation period. Based on age, patients in their 50s were the most common (16.5%). Regarding the severity, the ratio of mild was higher in under patients under 9 (99.3%); the ratio of severe was higher for patients in their 20s (4.6%). In almost every age group, the male ratio of TBI was higher, except for females aged 70 or older. Under 19 years of age, the ambulance utilization rate was lower than any other age group. The most common injury mechanism was a collision, the next was a traffic accident, and in under 9, a fall was the most common. 70.1% of patients returned home after treatments.
Identifying the characteristics of patients with TBI visiting ED is fundamental. Therefore, it is necessary to continuously collect basic data on TBI among patients visiting the ED.
Given its diverse disease courses and symptom presentations, multiple phenotype dimensions with different biological underpinnings are expected with bipolar disorders (BPs). In this study, we aimed to identify lifetime BP psychopathology dimensions. We also explored the differing associations with bipolar I (BP-I) and bipolar II (BP-II) disorders.
We included a total of 307 subjects with BPs in the analysis. For the factor analysis, we chose six variables related to clinical courses, 29 indicators covering lifetime symptoms of mood episodes, and 6 specific comorbid conditions. To determine the relationships among the identified phenotypic dimensions and their effects on differentiating BP subtypes, we applied structural equation modeling.
We selected a six-factor solution through scree plot, Velicer's minimum average partial test, and face validity evaluations; the six factors were cyclicity, depression, atypical vegetative symptoms, elation, psychotic/irritable mania, and comorbidity. In the path analysis, five factors excluding atypical vegetative symptoms were associated with one another. Cyclicity, depression, and comorbidity had positive associations, and they correlated negatively with psychotic/irritable mania; elation showed positive correlations with cyclicity and psychotic/irritable mania. Depression, cyclicity, and comorbidity were stronger in BP-II than in BP-I, and they contributed significantly to the distinction between the two disorders.
We identified six phenotype dimensions; in addition to symptom features of manic and depressive episodes, various comorbidities and high cyclicity constructed separate dimensions. Except for atypical vegetative symptoms, all factors showed a complex interdependency and played roles in discriminating BP-II from BP-I.
We trace Sn nanoparticles (NPs) produced from SnO2 nanotubes (NTs) during lithiation initialized by high energy e-beam irradiation. The growth dynamics of Sn NPs is visualized in liquid electrolytes by graphene liquid cell transmission electron microscopy. The observation reveals that Sn NPs grow on the surface of SnO2 NTs via coalescence and the final shape of agglomerated NPs is governed by surface energy of the Sn NPs and the interfacial energy between Sn NPs and SnO2 NTs. Our result will likely benefit more rational material design of the ideal interface for facile ion insertion.
The Saemangeum tidal flat, an important staging site for migratory shorebirds that travel the East Asian-Australasian (EAA) Flyway, was isolated from the eastern Yellow Sea in 2006 as part of a large-scale reclamation project. To gain a better understanding of the impacts that this reclamation has had on the long-distance migratory shorebirds that use the EAA Flyway, we examined the number of shorebirds visiting Saemangeum and three adjacent sites in the Geum Estuary (Yubu Island, the Janghang coastline, and the Geum River Channel) during the spring and fall prior to, and after, completion of the reclamation (2004–2013). A total of 48 shorebird species, including one Critically Endangered, three Endangered, and nine Near Threatened species, were observed over this period. Peak numbers of shorebirds recorded at sites in Saemangeum and the Geum Estuary following completion of the project were 74% below those recorded in 2004 and 2005, the years prior to reclamation activity. In Saemangeum, shorebird abundance declined by approximately 95% and 97.3% during the northward and southward migrations, respectively, as a result of reclamation. Although shorebird populations in the Geum Estuary increased by 5% and 20% during the northwards and southward migrations, respectively, these increases failed to offset the reduction in shorebird abundance in Saemangeum; overall, shorebird abundance at Saemangeum and the three adjacent sites in the Geum Estuary markedly declined over the reclamation period. Given the more favourable conditions of adjacent areas, sites in Saemangeum and the Geum Estuary no longer provide the habitat conditions necessary for long-distance migratory shorebirds. In order to improve habitat for staging migratory birds, we suggest that measures such as the conversion of an abandoned salt farm for use as roosting sites, the construction of artificial barriers to prevent human disturbance, and re-opening of the river-banks to facilitate water flow be implemented.
Family study can provide estimates of overall genetic influences on a particular trait because family relationships provide accurate measures of average genetic sharing. However, evidence of genetic contributions to skin phenotypes is limited, which may preclude genetic studies to identify genetic variants or to understand underlying molecular biology of skin traits. This study aimed to estimate genetic and environmental contributions to selected dermatologic phenotypes, that is, to melanin index, sebum secretion, and skin humidity level in a Korean twin-family cohort. We investigated more than 2,000 individuals from 486 families, including 388 monozygotic twin pairs and 82 dizygotic twin pairs. Variance component method was used to estimate genetic influences in terms of heritability. Heritability of skin melanin index, sebum secretion, and skin humidity (arm and cheek) were estimated to be 0.44 [95% CI 0.38–0.49], 0.21 [95% CI 0.16–0.26], 0.13 [95% CI 0.07–0.18], and 0.11 [95% CI 0.06–0.16] respectively, after adjusting for confounding factors. Our findings suggest that genetics play a major role on skin melanin index, but only mild roles on sebum secretion and humidity. Sebum secretion and skin humidity are controlled predominantly by environmental factors notably on shared environments among family members. We expect that our findings add insight to determinants of common dermatologic traits, and serve as a reference for biologic studies.