Representation of the hierarchical and functional structure of an ambulatory network of medical consultations through Social Network Analysis, with an emphasis on the role of medical specialties.

BACKGROUND: Ambulatory Health Care Networks (Amb-HCN) are circuits of patient referral and counter-referral that emerge, explicitly or spontaneously, between doctors who provide care in their offices. Finding a meaningful analytical representation for the organic and hierarchical functioning of an Amb-HCN may have managerial and health policymaking implications. We aimed to characterize the structural and functional topology of an Amb-HCN of a private health insurance provider (PHIP) using objective metrics from graph theory. METHODS: This is a cross-sectional quantitative study with a secondary data analysis study design. A Social Network Analysis (SNA) was conducted using office visits performed between April 1, 2021 and May 15, 2022, retrieved from secondary administrative claim databases from a PHIP in Belo Horizonte, Southeastern Brazil. Included were beneficiaries of a healthcare plan not restricting the location or physician caring for the patient. A directional and weighted network was constructed, where doctors were the vertices and patient referrals between doctors, within 7-45 days, were the network edges. Vertex-level SNA measures were calculated and grouped into three theoretical constructs: patient follow-up (aimed at assessing the doctor's pattern of patient follow-up); relationship with authorities (which assessed whether the doctor is an authority or contributes to his or her colleague's authority status); and centrality (aimed at positioning the doctor relative to the network graph). To characterize physician profiles within each dimension based on SNA metrics results, a K-means cluster analysis was conducted. The resulting physician clusters were assigned labels that sought to be representative of the observed values of the vertex metrics within the clusters. FINDINGS: Overall, 666,263 individuals performed 3,863,222 office visits with 4,554 physicians. A total of 577 physicians (12.7%) had very low consultation productivity and contributed very little to the network (i.e., about 1.1% of all referrals made or received), being excluded from subsequent doctor profiles analysis. Cluster analysis found 951 (23.9%) doctors to be central in the graph and 1,258 (31.6%) to be peripheral; 883 (22.2%) to be authorities and 266 (6.7%) as seeking authorities; 3,684 (92.6%) mostly shared patients with colleagues, with patient follow-up intensities ranging from weak to strong. Wide profile dispersion was observed among specialties and, more interestingly, within specialties. Non-primary-care medical specialties (e.g., cardiology, endocrinology etc.) were associated with central profile in the graph, while surgical specialties predominated in the periphery, along with pediatrics. Only pediatrics was associated with strong and prevalent (i.e., low patient sharing pattern) follow-up. Many doctors from internal medicine and family medicine had unexpectedly weak and shared patient follow-up profiles. Doctor profiles exhibited pairwise relationships with each other and with the number of chronic comorbidities of the patients they treated. For example, physicians identified as authorities were frequently central and treated patients with more comorbidities. Ten medical communities were identified with clear territorial and specialty segregation. CONCLUSIONS: Viewing the Amb-HCN as a social network provided a topological and functional representation with potentially meaningful and actionable emerging insights into the most influential actors and specialties, functional hierarchies, factors that lead to self-constituted medical communities, and dispersion from expected patterns within medical specialties.

ICU Admission, Invasive Mechanical Ventilation, and Mortality among Children and Adolescents Hospitalized for COVID-19 in a Private Healthcare System.

Aim: The COVID-19 pandemic devastated healthcare around the world. Data about the COVID-19 outcomes among young people are still scarce. We aim to identify factors associated with the composite outcome among children and adolescents hospitalized due to COVID-19. Methods: We performed a search in the database of a large Brazilian private healthcare system. Insured people aged 21 years or younger who were hospitalized due to COVID-19 from Feb/28th/2020 to Nov/1st/2021 were included. The primary endpoint was the composite outcome consisting of ICU admission, need for invasive mechanical ventilation, or death. Results: We evaluated 199 patients who had an index hospitalization due to COVID-19. The median monthly rate of index hospitalization was 2.7 (interquartile range [IQR], 1.6-3.9) per 100,000 clients aged 21 years or less. The median age of the patients was 4.5 years (IQR, 1.4-14.1). At the index hospitalization, the composite outcome rate was 26.6%. The composite outcome was associated with all the previous coexisting morbidities evaluated. The median follow-up was 249.0 days (IQR, 152.0-438.5). There were 27 readmissions (16 patients) within 30 days after the discharge. Conclusions: In conclusion, hospitalized children and adolescents had a composite outcome rate of 26.6% at the index hospitalization. Having previous chronic morbidity was associated with the composite.

Virologic and immunologic effectiveness of darunavir-based salvage therapy in HIV-1-infected adults in a Brazilian clinical practice setting: results of a multicenter and retrospective cohort study

Background: Darunavir has been proven efficacious for antiretroviral-experienced HIV-1-infected patients in randomized trials. However, effectiveness of darunavir-based salvage therapy is understudied in routine care in Brazil. Methods: Retrospective cohort study of HIV-1-infected patients from three public referral centers in Belo Horizonte, who received a darunavir-based therapy between 2008 and 2010, after virologic failure. Primary endpoint was the proportion of patients with viral load <50 copies/mL at week 48. Change in CD4 cell count was also evaluated. Outcome measures were analyzed on an intent-to-treat basis applied to observational studies. Sensitivity analysis was conducted to evaluate the impact of missing data at week 48. Predictors of virologic failure were examined using rare-event, finite sample, bias-corrected logistic regression. Results: Among 108 patients, the median age was 44.2 years, and 72.2% were male. They had long-standing HIV-1 infection (median 11.6 years) and advanced disease (76.9% had an AIDS-defining event). All patients had previously received protease inhibitors and nucleoside reverse transcriptase inhibitors, 75% nonnucleoside reverse transcriptase inhibitors, and 4.6% enfuvirtide. The median length of protease inhibitor use was 8.9 years, and 90.8% of patients had prior exposure to unboosted protease inhibitor. Genotypic resistance profile showed a median of three primary protease inhibitor mutations and 10.2% had three or more darunavir resistance-associated mutations. Virologic success at week 48 was achieved by 78.7% (95% CI = 69.7–86%) of patients and mean CD4 cell count increase from baseline was 131.5 cells/μL (95% CI = 103.4–159.6). In multiple logistic regression analysis, higher baseline viral load (RR = 1.04 per 10,000 copies/mL increase; 95% CI = 1.01–1.09) and higher number of darunavir resistance-associated mutations (RR = 1.23 per each; 95% CI = 0.95–1.48) ...

Virologic and immunologic effectiveness at 48 weeks of darunavir-ritonavir-based regimens in treatment-experienced persons living with HIV-1 infection in clinical practice: a multicenter Brazilian cohort.

INTRODUCTION: Published data addressing the effectiveness of darunavir-ritonavir (DRV/r)-based therapy for multiexperienced patients in developing countries are scarce. This study evaluated the 48-week virologic and immunologic effectiveness of salvage therapy based on DRV/r for the treatment of multidrug-experienced HIV-1-infected adults in Brazil. MATERIALS AND METHODS: A multicenter retrospective cohort study was carried out with multidrug-experienced adults who were on a failing antiretroviral therapy and started a DRV/r-based salvage therapy between 2008 and 2010. The primary effectiveness end point was the proportion of patients with virologic success (plasma HIV-1 RNA <50 copies/mL at week 48). RESULTS: At 48 weeks, 73% of the patients had HIV-RNA <50 copies/mL and a mean increase of 108 CD4 cells/mm(3). Higher baseline viral load, lower baseline CD4 count, younger age, and 3 or more DRV/r-associated resistance mutations were significantly predictive of virologic failure. Concomitant use of raltegravir was strongly associated with virologic success. CONCLUSION: The use of DRV/r-based regimens for salvage therapy is an effective strategy in the clinical care setting of a developing country.

Virologic and immunologic effectiveness of darunavir-based salvage therapy in HIV-1-infected adults in a Brazilian clinical practice setting: results of a multicenter and retrospective cohort study.

BACKGROUND: Darunavir has been proven efficacious for antiretroviral-experienced HIV-1-infected patients in randomized trials. However, effectiveness of darunavir-based salvage therapy is understudied in routine care in Brazil. METHODS: Retrospective cohort study of HIV-1-infected patients from three public referral centers in Belo Horizonte, who received a darunavir-based therapy between 2008 and 2010, after virologic failure. Primary endpoint was the proportion of patients with viral load<50 copies/mL at week 48. Change in CD4 cell count was also evaluated. Outcome measures were analyzed on an intent-to-treat basis applied to observational studies. Sensitivity analysis was conducted to evaluate the impact of missing data at week 48. Predictors of virologic failure were examined using rare-event, finite sample, bias-corrected logistic regression. RESULTS: Among 108 patients, the median age was 44.2 years, and 72.2% were male. They had long-standing HIV-1 infection (median 11.6 years) and advanced disease (76.9% had an AIDS-defining event). All patients had previously received protease inhibitors and nucleoside reverse transcriptase inhibitors, 75% nonnucleoside reverse transcriptase inhibitors, and 4.6% enfuvirtide. The median length of protease inhibitor use was 8.9 years, and 90.8% of patients had prior exposure to unboosted protease inhibitor. Genotypic resistance profile showed a median of three primary protease inhibitor mutations and 10.2% had three or more darunavir resistance-associated mutations. Virologic success at week 48 was achieved by 78.7% (95% CI=69.7-86%) of patients and mean CD4 cell count increase from baseline was 131.5 cells/µL (95% CI=103.4-159.6). In multiple logistic regression analysis, higher baseline viral load (RR=1.04 per 10,000 copies/mL increase; 95% CI=1.01-1.09) and higher number of darunavir resistance-associated mutations (RR=1.23 per each; 95% CI=0.95-1.48) were independently associated with virologic failure. CONCLUSION: Virologic suppression is a realistic endpoint for most treatment-experienced patients who begin a darunavir-based therapy outside the controlled conditions of a randomized trial, at routine care settings.

Avaliação de efetividade da atenção domiciliar de uma cooperativa médica de Belo Horizonte, Minas Gerais, Brasil / Home care effectiveness assessment in a health maintenance organization in Belo Horizonte, Minas Gerais State, Brazil / Evaluación de la eficacia de un programa de atención domiciliaria en una cooperativa médica de Belo Horizonte, Minas Gerais, Brasil

A retrospective cohort study was performed to assess the impact of a Case Management Home Care Program supplied by the Unimed-BH medical cooperative on hospitalization-free survival time among eligible patients 60 years or older. A Cox proportional hazards model was fitted to assess the impact of home visits by health professionals on hospitalization-free survival time in a sample of 2,943 elders, while adjusting for patient age, physical dependence, medicines, feeding route, pressure ulcers, supplemental oxygen therapy, cognitive impairment, outpatient visits, and hospitalizations in the preceding quarter. Risk factors for shorter hospitalization-free survival time were: degree of physical dependence, enteral nutrition, supplemental oxygen therapy, pressure ulcers, and hospital admissions in the previous quarter. Higher rates of home visits by physicians and nurses showed a protective dose-response effect on hospitalization-free survival time. The data suggest that regular home visits by physicians and nurses lengthen hospitalization-free survival time among elderly patients enrolled in the program.

Foi realizado estudo de coorte retrospectiva com o objetivo de avaliar o impacto do plano de cuidados do Programa de Atenção Domiciliar da Unimed-BH, modalidade Gerenciamento de Casos (PrGC/AD), sobre o tempo livre de hospitalização entre os pacientes com 60 anos ou mais assistidos pelo programa. Utilizou-se o modelo de Cox para avaliar o efeito do intervalo entre as visitas domiciliares dos profissionais do programa sobre o tempo livre de hospitalização de 2.943 idosos, ajustado por idade, medicamentos em uso, via de alimentação, úlcera de pressão, déficit cognitivo, dependência física, oxigenioterapia, consultas ambulatoriais e hospitalizações no trimestre anterior. Foram fatores de risco para menor tempo livre de hospitalização: o grau de dependência física, alimentação enteral, oxigenioterapia suplementar, úlceras de pressão e hospitalizações no trimestre anterior. Observouse efeito protetor dose-resposta da frequência de visitas médicas e de enfermagem. Os resultados sugerem que visitas domiciliares regulares de médico e enfermeiro aumentam significativamente o tempo livre de hospitalização nos pacientes assistidos pelo PrGC/AD.

Se realizó un estudio de cohorte retrospectivo para evaluar el impacto de un plan de asistencia del Programa de Atención Domiciliaria de Unimed-BH, modalidad de Gestión de Casos (PrGC/AD), sobre el tiempo libre de hospitalización en pacientes con 60 años o más. Se usó el modelo de riesgos proporcionales de Cox para evaluar el efecto del intervalo entre las visitas domiciliarias de los profesionales del programa sobre el tiempo libre de hospitalización de 2.943 ancianos, ajustado por edad, medicamentos usados, vía de alimentación, úlcera por presión, deterioro cognitivo, dependencia física, oxigenoterapia, consultas ambulatorias y hospitalizaciones en el trimestre anterior. Fueron factores de riesgo para un menor tiempo libre de hospitalización: grado de dependencia física, alimentación enteral, oxigenoterapia suplementaria, úlcera por presión y hospitalizaciones en el trimestre anterior. Las frecuencias de visitas médicas y de enfermeros tuvieron un efecto protector dosis-respuesta. Los resultados sugieren que las visitas domiciliarias regulares de médico y enfermero aumentan el tiempo libre de hospitalización en los pacientes asistidos por el PrGC/AD.

[Home care effectiveness assessment in a health maintenance organization in Belo Horizonte, Minas Gerais State, Brazil]. / Avaliação de efetividade da atenção domiciliar de uma cooperativa médica de Belo Horizonte, Minas Gerais, Brasil.

A retrospective cohort study was performed to assess the impact of a Case Management Home Care Program supplied by the Unimed-BH medical cooperative on hospitalization-free survival time among eligible patients 60 years or older. A Cox proportional hazards model was fitted to assess the impact of home visits by health professionals on hospitalization-free survival time in a sample of 2,943 elders, while adjusting for patient age, physical dependence, medicines, feeding route, pressure ulcers, supplemental oxygen therapy, cognitive impairment, outpatient visits, and hospitalizations in the preceding quarter. Risk factors for shorter hospitalization-free survival time were: degree of physical dependence, enteral nutrition, supplemental oxygen therapy, pressure ulcers, and hospital admissions in the previous quarter. Higher rates of home visits by physicians and nurses showed a protective dose-response effect on hospitalization-free survival time. The data suggest that regular home visits by physicians and nurses lengthen hospitalization-free survival time among elderly patients enrolled in the program.

Performance, revision, and extension of the National Nosocomial Infections Surveillance system's risk index in Brazilian hospitals.

OBJECTIVE: To assess the benefit of using procedure-specific alternative cutoff points for National Nosocomial Infections Surveillance (NNIS) risk index variables and of extending surgical site infection (SSI) risk prediction models with a postdischarge surveillance indicator. DESIGN: Open, retrospective, validation cohort study. SETTING: Five private, nonuniversity Brazilian hospitals. PATIENTS: Consecutive inpatients operated on between January 1993 and May 2006 (other operations of the genitourinary system [n = 20,723], integumentary system [n = 12,408], or musculoskeletal system [n = 15,714] and abdominal hysterectomy [n = 11,847]). METHODS: For each procedure category, development and validation samples were defined nonrandomly. In the development samples, alternative SSI prognostic scores were constructed using logistic regression: (i) alternative NNIS scores used NNIS risk index covariates and cutoff points but locally derived SSI risk strata and rates, (ii) revised scores used procedure-specific alternative cutoff points, and (iii) extended scores expanded revised scores with a postdischarge surveillance indicator. Performances were compared in the validation samples using calibration, discrimination, and overall performance measures. RESULTS: The NNIS risk index showed low discrimination, inadequate calibration, and predictions with high variability. The most consistent advantage of alternative NNIS scores was regarding calibration (prevalence and dispersion components). Revised scores performed slightly better than the NNIS risk index for most procedures and measures, mainly in calibration. Extended scores clearly performed better than the NNIS risk index, irrespective of the measure or operative procedure. CONCLUSIONS: Locally derived SSI risk strata and rates improved the NNIS risk index's calibration. Alternative cutoff points further improved the specification of the intrinsic SSI risk component. Controlling for incomplete postdischarge SSI surveillance provided consistently more accurate SSI risk adjustment.

Accounting for incomplete postdischarge follow-up during surveillance of surgical site infection by use of the National Nosocomial Infections Surveillance system's risk index.

OBJECTIVE: We examined the usefulness of a simple method to account for incomplete postdischarge follow-up during surveillance of surgical site infection (SSI) by use of the National Nosocomial Infections Surveillance (NNIS) system's risk index. DESIGN: Retrospective cohort study that used data prospectively collected from 1993 through 2006. SETTING: Five private, nonuniversity healthcare facilities in Belo Horizonte, Brazil. PATIENTS: Consecutive patients undergoing the following NNIS operative procedures: 20,981 operations on the genitourinary system, 11,930 abdominal hysterectomies, 7,696 herniorraphies, 6,002 cholecystectomies, and 6,892 laparotomies. METHODS: For each operative procedure category, 2 SSI risk models were specified. First, a model based on the NNIS system's risk index variables was specified (hereafter referred to as the NNIS-based model). Second, a modified model (hereafter referred to as the modified NNIS-based model), which was also based on the NNIS system's risk index, was specified with a postdischarge surveillance indicator, which was assigned the value of 1 if the patient could be reached during follow-up and a value of 0 if the patient could not be reached. A formal comparison of the capabilities of the 2 models to assess the risk of SSI was conducted using measures of calibration (by use of the Pearson goodness-of-fit test) and discrimination (by use of receiver operating characteristic curves). Goodman-Kruskal correlations (G) were also calculated. RESULTS: The rate of incomplete postdischarge follow-up varied between 29.8% for abdominal hysterectomies and 50.5% for cholecystectomies. The modified NNIS-based model for laparotomy did not show any significant benefit over the NNIS-based model in any measure. For all other operative procedures, the modified NNIS-based model showed a significantly improved discriminatory ability and higher G statistics, compared with the NNIS-based model, with no significant impairment in calibration, except if used to assess the risk of SSI after operations on the genitourinary system or after a cholecystectomy. CONCLUSIONS: Compared with the NNIS-based model, the modified NNIS-based model added potentially useful clinical information regarding most of the operative procedures. Further work is warranted to evaluate this method for accounting for incomplete postdischarge follow-up during surveillance of SSI.

Rates of surgical site infection as a performance measure: Are we ready?

With the introduction of quality assurance in health care delivery, there has been a proliferation of research studies that compare patient outcomes for similar conditions among many health care delivery facilities. Since the 1990s, increasing interest has been placed in the incorporation of clinical adverse events as quality indicators in hospital quality assurance programs. Adverse post-operative events, and very especially surgical site infection (SSI) rates after specific procedures, gained popularity as hospital quality indicators in the 1980s. For a SSI rate to be considered a valid indicator of the quality of care, it is essential that a proper adjustment for patient case mix be performed, so that meaningful comparisons of SSI rates can be made among surgeons, institutions, or over time. So far, a significant impediment to developing meaningful hospital-acquired infection rates that can be used for intra- and inter-hospital comparisons has been the lack of an adequate means of adjusting for case mix. This paper discusses what we have learned in the last years regarding risk adjustment of SSI rates for provider performance assessment, and identifies areas in which significant improvement is still needed.