Deep-Learning-Based Automated Anomaly Detection of EEGs in Intensive Care Units.

An intensive care unit (ICU) is a special ward in the hospital for patients who require intensive care. It is equipped with many instruments monitoring patients' vital signs and supported by the medical staff. However, continuous monitoring demands a massive workload of medical care. To ease the burden, we aim to develop an automatic detection model to monitor when brain anomalies occur. In this study, we focus on electroencephalography (EEG), which monitors the brain electroactivity of patients continuously. It is mainly for the diagnosis of brain malfunction. We propose the gated-recurrent-unit-based (GRU-based) model for detecting brain anomalies; it predicts whether the spike or sharp wave happens within a short time window. Based on the banana montage setting, the proposed model exploits characteristics of multiple channels simultaneously to detect anomalies. It is trained, validated, and tested on separated EEG data and achieves more than 90% testing performance on sensitivity, specificity, and balanced accuracy. The proposed anomaly detection model detects the existence of a spike or sharp wave precisely; it will notify the ICU medical staff, who can provide immediate follow-up treatment. Consequently, it can reduce the medical workload in the ICU significantly.

MMP-9 upregulation may predict hemorrhagic transformation after endovascular thrombectomy.

Background: Hemorrhagic transformation (HT) is a serious complication after endovascular thrombectomy (EVT) for patients with acute ischemic stroke (AIS). We analyzed the plasma levels of MMP-9 before and after EVT and assessed the temporal changes of MMP-9 that may be associated with, and therefore predict, HT after EVT. Methods: We enrolled 30 AIS patients who received EVT, and 16 (53.3%) developed HT. The levels of MMP-9 in plasma collected from the arteries of AIS patients before and immediately after EVT were measured using ELISA. The percent change in MMP-9 after EVT (after/before) was calculated and compared between patients with and without HT. Results: The median age of the AIS patients was 70 years, and 13 patients (43.3%) were men. The median National Institutes of Health Stroke Scale (NIHSS) scores of patients with HT were 18 on admission and 18 after EVT. The median NIHSS scores of patients without HT were 17 on admission and 11 after EVT. Patients with HT demonstrated significantly greater percentage increases in arterial MMP-9 levels after EVT. Conclusion: Patients with AIS who developed HT had significantly increased arterial MMP-9 levels after EVT, suggesting that the upregulation of MMP-9 following EVT could serve as a predictive biomarker for HT.

Ten-year follow-up investigation of stroke risk in systemic lupus erythematosus.

BACKGROUND AND PURPOSE: To analyse the long-term risk of ischaemic stroke and the clinical effects of antithrombotics on the risk of haemorrhagic stroke in patients with systemic lupus erythematosus (SLE). METHODS: A retrospective cohort study was conducted using a population-based database taken from Taiwan National Health Insurance Research Database. Patients with SLE between 2000 and 2008 were registered and matched with two controls by the index date, age, gender and Charlson Comorbidity Index (CCI). These subjects were followed until either stroke event or 31 December 2013. Adjusted HRs (aHRs) for strokes were estimated with Cox regression models, and the cumulative incidence of ischaemic stroke was analysed by log-rank test and Kaplan-Meier survival analysis. RESULTS: In total, 8310 patients with SLE and 16 620 patients without SLE were included. In general, patients with SLE had higher rates of ischaemic stroke (5.4% vs 3.3%) and haemorrhagic stroke (1.5% vs 0.6%) than in controls. In multivariate analysis adjusted to age, gender, CCI, urbanisation level and antithrombotics uses, aHRs of all strokes, ischaemic stroke and haemorrhagic stroke were 1.73 (95% CI: 1.54 to 1.94), 1.65 (95% CI: 1.45 to 1.87) and 2.24 (95% CI: 1.71 to 2.95), respectively, in patients with SLE. Patients with SLE were significantly more likely to suffer ischaemic stroke than patients without SLE, even 10 years after SLE diagnosis (6.12% vs 3.50%, p<0.001). Antiplatelet use increased the risk of haemorrhagic stroke in SLE group (aHR=1.74, 95% CI: 1.18 to 2.57). CONCLUSIONS: Patients with SLE are at greater risk of developing ischaemic stroke that lasts for 10 years. Antiplatelets should be carefully administered to prevent cardiovascular events in patients with SLE due to the risk of haemorrhagic stroke.

Dual antiplatelet therapy is associated with favorable outcome in acute minor stroke with an onset-to-door time beyond 24 h.

BACKGROUND/PURPOSE: In patients with noncardioembolic acute minor ischemic stroke (AMIS), dual antiplatelet therapy (DAPT) with aspirin plus clopidogrel within 24 h after stroke onset was more effective than aspirin alone. This study investigated the efficacy and safety of DAPT in AMIS patients with an onset-to-door time (OTDT) of more than 24 h. METHODS: This was a retrospective analysis of a prospective stroke registry from 2015 to 2021. Patients with AMIS and an OTDT within seven days were classified into the Early (≤24 h) and Late groups (>24 h) according to the time of antiplatelet administration after stroke onset. RESULTS: In total, 691 patients were identified. Of these, 446 (64.5%) and 245 (35.5%) patients were classified into the Early and Late groups, respectively. The rates of recurrent infarction and symptomatic intracranial hemorrhage at 90 days were similar between the single antiplatelet therapy (SAPT) and DAPT subgroups in both the Early and Late groups. More patients in the DAPT subgroup had a favorable outcome (modified Rankin scale of 0-1) at 90 days in both Early (84.2% versus 75.0%, p = 0.016) and Late (88.2% versus 76.9%, p = 0.040) groups. DAPT was independently associated with a favorable outcome in both the Early (odds ratio, 1.95; 95% CI, 1.15-3.32; p = 0.013) and Late (odds ratio, 2.72; 95% CI, 1.14-6.48; p = 0.024) groups. CONCLUSION: In patients with AMIS and an OTDT of more than 24 h, DAPT was associated with a favorable outcome at 90 days.

Use of dipeptidyl peptidase-4 inhibitors was associated with a lower risk of Parkinson's disease in diabetic patients.

Diabetes mellitus is a risk factor for Parkinson's disease (PD). While animal studies have supported the benefits of incretin-based therapies, including dipeptidyl peptidase-4 (DPP4) inhibitors, in PD, clinical research has yielded controversial results. This cohort study aimed to assess the relationship between PD incidence and the utilization of DPP4 inhibitor in diabetic patients. Using Taiwan's National Health Insurance Research Database from 2009 to 2018, diabetic patients receiving metformin plus at least one second-line oral antidiabetic (OAD) were enrolled. The patients were categorized as DPP4 inhibitor users and non-users. Propensity score matching was employed to establish a 1:1 ratio between DPP4 inhibitor users and non-users. Among the 205,910 patients enrolled, 149 were diagnosed with PD during follow-up. The incidence rate was 0.29 per 1000 person-years for DPP4 inhibitor users and 0.55 per 1000 person-years for the non-users. DPP4 inhibitor users exhibited a significantly lower risk of PD (adjusted hazard ratio, 0.51; 95% CI 0.39-0.68). Among DPP4 inhibitor users, vildagliptin showed the strongest correlation with a reduction in the risk of PD. This study demonstrates that the use of DPP4 inhibitors along with metformin in diabetic patients is associated with a lower risk of PD compared to those using other OADs.

Patent foramen ovale closure in non-elderly and elderly patients with cryptogenic stroke: a hospital-based cohort study.

Introduction: The efficacy of patent foramen ovale (PFO) closure in the elderly population is unclear. We aimed to investigate the efficacy and safety of PFO closure in non-elderly and elderly patients. Methods: Patients over 18 years of age with cryptogenic stroke (CS) or transient ischemic attack and PFO were prospectively enrolled and classified into two groups according to treatment: (1) closure of PFO (the PFOC group) and (2) medical treatment alone (the non-PFOC group). The primary outcome was a composite of recurrent cerebral ischemic events and all-cause mortality during the follow-up period. A modified Ranking Scale [mRS] at 180 days was recorded. The safety outcomes were procedure-related adverse events and periprocedural atrial fibrillation. The results between the PFOC and non-PFOC groups in non-elderly (<60 years) and elderly (≥60 years) patients were compared. Results: We enrolled 173 patients, 78 (45%) of whom were elderly. During a mean follow-up of 2.5 years, the incidence of primary outcome was significantly lower in the PFOC group (6.2% vs. 17.1%, hazard ratio[HR] = 0.35, 95% CI 0.13-0.97, p = 0.043) in adjusted Cox regression analysis. Compared with the non-PFOC group, the PFOC group had a numerically lower risk of the primary outcome in both the elderly (HR 0.26, 95% CI 0.07-1.01, p = 0.051) and the non-elderly (HR 0.61, 95% CI 0.11-3.27, p = 0.574) groups. In addition, patients with PFO closure in the elderly group had a lower median mRS at 180 days (p = 0.002). The rate of safety outcome was similar between the non-elderly and elderly groups. Discussion: PFO closure was associated with a reduced risk of the primary outcome in patients with PFO and CS in our total cohort, which included non-elderly and elderly patients. Compared to those without PFO closure, elderly patients with PFO closure had a better functional outcome at 180 days. PFO closure might be considered in selected elderly patients with PFO.

Severe lupus flare is associated with a much higher risk of stroke among patients with SLE.

BACKGROUND AND AIM: There are few data on the influence of lupus flare on stroke risk in systemic lupus erythematosus (SLE). In this study, we examined whether a severe lupus flare further increases the risk of stroke among SLE patients. METHODS: Using the Taiwan's National Health Insurance Research Database, we conducted a retrospective population-based cohort study from 2000 to 2016. Each patient with SLE was matched to a non-SLE subject in age, sex, and index date. A severe flare of lupus was identified when an SLE patient was admitted for pulse therapy with intravenous methylprednisolone greater than 250 mg in a single hospitalization. SLE patients were divided into severe flare and non-severe flare groups. RESULTS: In total, 334 of 10,006 patients with SLE had a severe lupus flare, and the remaining 9672 patients were assigned to the non-severe flare group. Ischemic stroke occurred in 29 (8.7%), 485 (5%), and 384 (3.8%) of the patients in the severe flare, non-severe flare, and control groups, respectively. Hemorrhagic stroke occurred in 9 (2.7%), 123 (1.3%), and 37 (0.4%) of patients in the severe flare, non-severe flare, and control groups, respectively. Compared with patients in the non-severe flare group, patients with severe flare had a significantly higher risk of ischemic stroke (adjusted hazard ratio (aHR) = 7.44, 95% confidence interval (CI): 4.93-11.25 vs aHR = 1.52, 95% CI: 1.26-1.83) and hemorrhagic stroke (aHR = 22.49, 95% CI: 10.09-50.12 vs aHR = 4.47, 95% CI: 2.90-6.90). CONCLUSION: Severe lupus flare is associated with a much higher risk of ischemic and hemorrhagic strokes among SLE patients.

Risk of Dementia after Exposure to Contrast Media: A Nationwide, Population-Based Cohort Study.

Contrast-medium-associated kidney injury is caused by the infusion of contrast media. Small vessel disease is significantly associated with various diseases, including simultaneous conditions of the kidney and brain, which are highly vulnerable to similar vascular damage and microvascular pathologies. Data to investigate the adverse effect of contrast media on the brain remain extremely lacking. In this study, 11,332,616 NHI enrollees were selected and divided into two groups, exposed and not exposed to a contrast medium during the observation period, from which 1,461,684 pairs were selected for analyses through matching in terms of age, sex, comorbidities, and frequency of outpatient visits during the previous year. In total, 1,461,684 patients exposed to a contrast medium and 1,461,684 controls not exposed to one were enrolled. In multivariable Cox proportional hazard models, patients exposed to a contrast medium had an overall 2.09-fold higher risk of dementia. In multivariable-stratified analyses, the risk of Alzheimer's disease was remarkably high in younger patients without any underlying comorbidity. This study is the first to discover that exposure to contrast media is significantly associated with the risk of dementia. A four-fold increased risk of vascular dementia was observed after exposure to a contrast medium. Further studies on the influence of exposure to contrast media on the brain are warranted.

Combined Functional Assessment for Predicting Clinical Outcomes in Stroke Patients After Post-acute Care: A Retrospective Multi-Center Cohort in Central Taiwan.

Background and Objective: In 2014, Taiwan's National Health Insurance administration launched a post-acute care (PAC) program for patients to improve their functions after acute stroke. The present study was aimed to determine PAC assessment parameters, either alone or in combination, for predicting clinical outcomes. Methods: We retrospectively enrolled stroke adult patients through one PAC network in central Taiwan between January 2014 and December 2020. We collected data on post-stroke patients' functional ability at baseline and after PAC stay. The comprehensive assessment included the following: Modified Rankin Scale (MRS), Functional Oral Intake Scale (FOIS), Mini-Nutritional Assessment (MNA), Berg Balance Scale (BBS), Fugl-Meyer Assessment (FMA), Mini-Mental State Examination (MMSE), aphasia test, and quality of life. The above items were assessed first at baseline and again at discharge from PAC. Logistic regression was used to determine factors that were associated with PAC length of stay (LOS), 14-day hospital readmission, and 1-year mortality. Results: A total of 267 adults (mean age 67.2 ± 14.7 years) with completed data were analyzed. MRS, activities of daily living (ADLs), instrumental activities of daily living (IADLs), BBS, and MMSE all had improved between disease onset and PAC discharge. Higher baseline and greater improvement of physical and cognitive functions between initial and final PAC assessments were significantly associated with less readmission, and lower mortality. Furthermore, the improved ADLs, FOIS, MNA, FMA-motor, and MMSE scores were related to LOS during PAC. Using logistic regression, we found that functional improvements ≥5 items [adjusted odds ratio (aOR) = 0.16; 95% confidence interval (CI) = 0.05-0.45] and improved MMSE (aOR = 0.19; 95% CI = 0.05-0.68) were significantly associated with reduced post-PAC mortality or readmission. Whereas, functional improvements ≥7 items, improved FOIS, and MNA significantly prolonged LOS during PAC. Conclusion: Physical performance parameters of patients with acute stroke improved after PAC. PAC assessment with multiple parameters better predicted clinical outcomes. These parameters could provide information on rehabilitation therapy for acute stroke patients receiving PAC.

Acute delirium as an initial manifestation of COVID-19 patients with acute ischemic stroke: Report on two cases.

Psychiatric and neurological complications of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are common. Psychiatric symptoms are so common that they are easily misinterpreted as an affective disorder induced by SARSCoV-2 infection. However, psychiatric symptoms, such as acute delirium, though rarely seen, can be the initial manifestations of acute ischemic stroke (AIS). These psychiatric symptoms may confuse the diagnosis of acute stroke, which needs correct and timely management. We report two hospitalized cases with SARS-CoV-2 infection and elevated serum D-dimer levels having acute delirium as the initial manifestation of AIS. The diagnostic processes were challenging and time-consuming, so reperfusion therapy could not be given in the therapeutic time window. The diagnoses of AIS were finally made by brain magnetic resonance imaging which showed diffusion restriction at the right middle cerebral artery territory in both cases. Features of psychiatric complications and stroke in coronavirus disease 2019 (COVID-19) patients are reviewed. For the hospitalized COVID-19 patients with elevated levels of serum Ddimer and acute delirium, acute stroke with neuropsychiatric manifestations should beconsidered.

Association between Early Absolute Neutrophil Count and Level of D-Dimer among Patients with COVID-19 Infection in Central Taiwan.

Thromboembolism is a critical event in patients with coronavirus disease (COVID)-19 infection and highly associated with neutrophil extracellular traps. D-dimer has been found to be an essential thromboembolism-associated biomarker; however, the association between absolute neutrophil count (ANC) and level of D-dimer in patients with COVID-19 infection remains unclear. In this study, we enrolled consecutive patients with COVID-19 admitted to Taichung Veterans General Hospital (TCVGH), a referral center in central Taiwan with 20 airborne infection isolation rooms. Spearman correlation was used to determine the association between ANC and level of D-dimer in distinct time periods. A total of 28 consecutive patients with COVID-19 infection were enrolled, and 32.1% (9/28) of them required mechanical ventilation. Patients requiring mechanical ventilation had a higher ANC (8225 vs. 3427/µL, p < 0.01) and levels of D-dimer (6.0 vs. 0.6 mg/L, p < 0.01) compared with those without mechanical ventilation. Notably, we identified five patients with image-proven thromboembolic events during the hospital course, with the number of patients with pulmonary embolism, venous thrombosis and acute ischemic stroke were 2, 1, and 2, respectively. We found that ANC within 4 days correlated with the level of D-dimer to a moderate level (r = 0.71, p < 0.05), and the association between ANC and D-dimer no longer exist after day 5. In conclusion, we found highly prevalent thromboembolic events among patients with severe COVID-19 infection in central Taiwan and identified the association between early ANC and D-dimer. More studies are warranted to elucidate the underlying mechanism.

Nephrotic Syndrome is Associated with Increased Risk of Ischemic Stroke.

BACKGROUND: To determine if the nephrotic syndrome (NS) is an independent risk factor of ischemic stroke. METHODS: This is a retrospective nationwide cohort study through an analysis of the National Health Insurance Research Database in Taiwan. To evaluate the risk of stroke, the corresponding controls were selected at a 4:1 ratio in the number of subjects, and they were matched with the study group in age, gender, Charlson comorbidity index (CCI), and index date. RESULTS: From a total of 16,245 surveyed subjects, ischemic stroke occurred in 1235 (7.6%) and hemorrhagic stroke in 129 (.74%) of them. The incidence of ischemic stroke was significantly higher in patients with NS (n = 3496) compared to control patients without NS (n = 13,984) (9.92 versus 7.10, per 1000 person-year, P < .001). In the multivariate analysis, the overall adjusted hazard ratio (aHR) of stroke in NS patients was 1.37 (95% CI, 1.21-1.54, P < .001). The risk factors of ischemic stroke were NS (aHR, 1.38 [95% confidence interval {CI}, 1.21-1.57]; P < .001), age greater than 45 years (aHR, 7.98 [95% CI, 6.47-9.48]; P < .001), male gender (aHR, 1.23 [95% CI, 1.10-1.38]; P < .001), CCI greater than or equal to 1 (aHR ≥ 1.25 in different CCI score groups, all at P ≤ .003), ischemic heart disease (aHR, 1.95 [95% CI, 1.67-2.29]; P < .001), heart failure (HR, 1.77 [95% CI, 1.30-2.42]; P < .001). Risk factors of hemorrhagic stroke were those aged greater than 45 years, or with systemic lupus erythematosus, but not NS. CONCLUSIONS: We provided the first evidence that patients with NS had an increased risk of ischemic stroke.

Unmasking adrenoleukodystrophy in a cohort of cerebellar ataxia.

Adrenoleukodystrophy (ALD) is a rare and progressive neurogenetic disease that may manifest disparate symptoms. The present study aims at investigating the role of ataxic variant of ALD (AVALD) in patients with adult-onset cerebellar ataxia, as well as characterizing their clinical features that distinguish AVALD from other cerebellar ataxias. Mutations in the ATP binding cassette subfamily D member 1 gene (ABCD1) were ascertained in 516 unrelated patients with ataxia. The patients were categorized into three groups: molecularly unassigned hereditary ataxia (n = 118), sporadic ataxia with autonomic dysfunctions (n = 296), and sporadic ataxia without autonomic dysfunctions (n = 102). Brain MRIs were scrutinized for white matter hyperintensity (WMH) in the parieto-occipital lobes, frontal lobes, corticospinal tracts, pons, middle cerebellar peduncles and cerebellar hemispheres. Two ABCD1 mutations (p.S108L and p.P623fs) previously linked to cerebral ALD and adrenomyeloneuropathy but not AVALD were identified. ALD accounts for 0.85% (1/118) of the patients with molecularly unassigned hereditary ataxia and 0.34% (1/296) of the patients with sporadic ataxia with autonomic dysfunctions. WMH in the corticospinal tracts and WMH in the cerebellar hemispheres were strongly associated with AVALD rather than other ataxias. To conclude, ALD accounts for approximately 0.39% (2/516) of adult-onset cerebellar ataxias. This study expands the mutational spectrum of AVALD and underscores the importance of considering ALD as a potential etiology of cerebellar ataxia.

Cobra bite wound infection caused by Shewanella algae.

Shewanella wound infections after snake bites are rare. We report the case of a Shewanella algae wound infection associated with a cobra bite in a 27-year-old woman. The isolate was confirmed by sequencing of the 16S ribosomal DNA gene. This case expands the reported spectrum of infection caused by S. algae and raises the possibility that S. algae could be a causative pathogen in wound infections resulting from snake bites.

Hendra virus vaccine, a one health approach to protecting horse, human, and environmental health.

In recent years, the emergence of several highly pathogenic zoonotic diseases in humans has led to a renewed emphasis on the interconnectedness of human, animal, and environmental health, otherwise known as One Health. For example, Hendra virus (HeV), a zoonotic paramyxovirus, was discovered in 1994, and since then, infections have occurred in 7 humans, each of whom had a strong epidemiologic link to similarly affected horses. As a consequence of these outbreaks, eradication of bat populations was discussed, despite their crucial environmental roles in pollination and reduction of the insect population. We describe the development and evaluation of a vaccine for horses with the potential for breaking the chain of HeV transmission from bats to horses to humans, thereby protecting horse, human, and environmental health. The HeV vaccine for horses is a key example of a One Health approach to the control of human disease.

Features and treatment modality of iliopsoas abscess and its outcome: a 6-year hospital-based study.

BACKGROUND: Percutaneous drainage (PCD) and surgical intervention are two primary treatment options for iliopsoas abscess (IPA). However, there is currently no consensus on when to use PCD or surgical intervention, especially in patients with gas-forming IPA. This study compared the characteristics of patients with gas-forming and non-gas forming IPA and their mortality rates under different treatment modalities. An algorithm for selecting appropriate treatment for IPA patients is proposed based on our findings. METHODS: Eighty-eight IPA patients between July 2007 and February 2013 were enrolled in this retrospective study. Patients < 18 years of age or with an incomplete course of treatment were excluded. Demographic information, clinical characteristics, and outcomes of different treatment approaches were compared between gas-forming IPA and non-gas forming IPA patients. RESULTS: Among the 88 enrolled patients, 27 (31%) had gas-forming IPA and 61 (69%) had non-gas forming IPA. The overall intra-hospital mortality rate was 25%. The gas-forming IPA group had a higher intra-hospital mortality rate (12/27, 44.0%) than the non-gas forming IPA group (10/61, 16.4%) (P < 0.001). Only 2 of the 13 patients in the gas-forming IPA group initially accepting PCD had a good outcome (success rate = 15.4%). Three of the 11 IPA patients with failed initial PCD expired, and 8 of the 11 patients with failed initial PCD accepted salvage operation, of whom 5 survived. Seven of the 8 gas-forming IPA patients accepting primary surgical intervention survived (success rate = 87.5%). Only 1 of the 6 gas-forming IPA patients who accepted antibiotics alone, without PCD or surgical intervention, survived (success rate = 16.7%). In the non-gas forming IPA group, 23 of 61 patients initially accepted PCD, which was successful in 17 patients (73.9%). The success rate of PCD was much higher in the non-gas forming group than in the gas-forming group (P <0.01). CONCLUSIONS: Based on the high failure rate of PCD and the high success rate of surgical intervention in our samples, we recommend early surgical intervention with appropriate antibiotic treatment for the patients with gas-forming IPA. Either PCD or primary surgical intervention is a suitable treatment for patients with non-gas forming IPA.

Clinical and microbiological features of shewanella bacteremia in patients with hepatobiliary disease.

OBJECTIVE: Shewanella bacteremia is an uncommon but potentially fatal disease. Although hepatobiliary diseases have been proposed to be risk factors for various Shewanella infections, little is known about the features of Shewanella bacteremia in patients with hepatobiliary diseases. This study aims to characterize the presentation and risk factors of Shewanella bacteremia in patients with hepatobiliary diseases. METHODS: We retrospectively investigated the clinical features, microbiology and outcomes of patients with Shewanella bacteremia who were admitted to a tertiary medical center between January 2001 and December 2010. All isolates were confirmed to the species level using 16S rRNA sequencing analyses. The English language medical literature was searched for previously published reports. RESULTS: Fifty-nine cases of Shewanella bacteremia, including nine at the hospital, were identified, 28 (47.4%) of which involved underlying hepatobiliary diseases, representing an important risk factor. In 12 of the 28 cases, the infections involved the hepatobiliary system; with a tendency towards an Asian origin. In our case series of nine patients, Shewanella haliotis was isolated in five patients. The majority of our patients lived in coastal areas, consumed seafood regularly and developed bacteremia during the summer season. CONCLUSION: It is recommended that the possibility for Shewanella infection be considered in patients with bacteremia and also underlying hepatobiliary diseases, particularly if patients present with hepatobiliary infections, a history of seafood, or development of the disease during the summer.

Perceptual market orientation gap and its impact on relationship quality and patient loyalty: the role of internal marketing.

The purpose of this study was to explore the perceptual market orientation gaps between physician and patients and its impact on relationship quality and patient loyalty, and to verify the critical role of internal marketing on developing market orientation. Self-administered questionnaires were then employed to collect the data. We used a convenience sample of physicians and patients at a medical center in central Taiwan, and 90 usable questionnaires from physicians and 450 usable questionnaires from patients were returned. Hierarchical multiple regression analyses were used to validate the research hypotheses. Physicians' perceptual market orientation had a positive influence on physician-patient relationship quality, hospital-patient relationship quality, and patient loyalty, but the perceptual market orientation gap between physicians and their patients had a direct negative impact on these constructs. Finally, internal marketing was found to have an influence on relationship quality and patient loyalty through the mediation of market orientation. In order to enhance relationship quality and patient loyalty, hospital managers should focus their efforts on improving employees' market orientation and reducing patients' perceptual market orientation gap. In addition, internal marketing was found to be a useful pathway in developing market orientation.