Medical care epidemiology and unwarranted variation: the Israeli case

Amiodarone and pulmonary toxicity in atrial fibrillation: a nationwide Israeli study

BACKGROUND AND AIMS

Amiodarone-related interstitial lung disease (ILD) is the most severe adverse effect of amiodarone treatment. Most data on amiodarone-related ILD are derived from periods when amiodarone was given at higher doses than currently used.

METHODS

A nationwide population-based study was conducted among patients with incident atrial fibrillation (AF) between 1 December 1999 and 31 December 31 2021. Amiodarone-exposed patients were matched 1:1 with controls unexposed to amiodarone based on age, sex, ethnicity, and AF diagnosis duration. The final patient cohort included only matched pairs where amiodarone therapy was consistent throughout follow-up. Directed acyclic graphs and inverse probability treatment weighting (IPTW) modelling were used. Patients with either prior ILD or primary lung cancer (PLC) were excluded. The primary outcome was the incidence of any ILD. Secondary endpoints were death and PLC.

RESULTS

The final cohort included 6039 amiodarone-exposed patients who were matched with unexposed controls. The median age was 73.3 years, and 51.6% were women. After a mean follow-up of 4.2 years, ILD occurred in 242 (2.0%) patients. After IPTW, amiodarone exposure was not significantly associated with ILD [hazard ratio (HR): 1.45, 95% confidence interval (CI): 0.97, 2.44, P = 0.09]. There was a trivial higher relative risk of ILD among amiodarone-exposed patients between Years 2 and 8 of follow-up [maximal risk ratio (RR): 1.019]. Primary lung cancer occurred in 97 (0.8%) patients. After IPTW, amiodarone was not associated with PLC (HR: 1.18, 95% CI: 0.76, 2.08, P = 0.53). All-cause death occurred in 2185 (18.1%) patients. After IPTW, amiodarone was associated with reduced mortality risk (HR: 0.65, 95% CI: 0.60, 0.72, P < 0.001). The results were consistent across a variety of sensitivity analyses.

CONCLUSION

In a contemporary AF population, low-dose amiodarone was associated with a trend towards increased risk of ILD (15%-45%) but a clinically negligible change in absolute risk (maximum of 1.8%), no increased risk of PLC, and a lower risk of all-cause mortality.

Predictors of Adverse Outcome in High-Risk Percutaneous Coronary Interventions Patients

BACKGROUND

Identifying high-risk percutaneous coronary intervention (PCI) patients is challenging. We aimed to evaluate which high-risk patients are prone to adverse events.

METHODS

We performed a retrospective study including consecutive high-risk PCIs from 2005 to 2018 in a large tertiary medical centre. Patients with unprotected left main (LM) disease, last patent coronary vessel, or 3-vessel coronary artery disease with left ventricular ejection fraction < 35% were included. A predictive 30-day major adverse cardiac events (MACE) score consisting of any myocardial infarction, all-cause death, or target-vessel revascularisation was constructed.

RESULTS

From 2005 to 2018, a total of 1890 patients who underwent PCI met the predefined high-risk PCI criteria. Mortality rate was 8.8% at 30 days and 20.7% at 1 year, and 30-day MACE rate was 14.2% and 33.5% at 1 year. Predictors of short-term MACE were New York Heart Association functional class (NYHA) 4 (hazard ratio [HR] 6.65; P < 0.001), systolic blood pressure (SBP) < 90 mm Hg (HR 4.93; P < 0.001), creatinine > 1.3 mg/dL (HR 3.57; P < 0.001), hemoglobin < 11.0 g/dL (HR 3.07; P < 0.001), pulmonary artery systolic pressure > 50 mm Hg (HR 2.06; P < 0.001), atrial fibrillation (HR 1.74; P < 0.001), and LM disease (HR 2.04; P < 0.001) or last patent vessel (HR 1.70; P = 0.002). A score constructed from these parameters reached a sensitivity of 90% and a specificity of 81% with areas under the receiver operating characteristic curve of 0.92 for MACE and 0.94 with 89% sensitivity and 87% specificity for all-cause mortality.

CONCLUSIONS

Specific features such as LM lesion or last patent conduit, pulmonary hypertension, atrial fibrillation, anemia, and renal failure, along with low SBP and NYHA 4, aid risk stratification and consideration of further treatment measures.

Unravelling the determinants of medical practice variation in referrals among primary care physicians: insights from a retrospective cohort study in Southern Israel

OBJECTIVES

Reducing medical practice variation (MPV) is a central theme of system improvement because it is associated with poor health outcomes, increased costs and disparities in care. This study aimed to estimate the extent to which each determinant (patient, physician, clinic) explains MPV among primary care physicians and to identify the characteristics of health services with a greater explained variance.

METHODS

A retrospective cohort study of primary care physicians practising in non-private clinics of Clalit Health Services in Southern Israel, for longer than a year between 2011 and 2017 and with more than 100 adult patients per practice. We assessed the variation in referral rates among 17 health services and the proportion explained by each domain (patient, physician and clinic). We used generalised linear negative binomial mixed models and the Nakagawa's R2, computing the marginal r2.

RESULTS

The study included 243 physicians working in 295 practices and 139 clinics. The mean-explained variance was 28.5%±10.0%, where physician characteristics explained 4.5% of the variation. The intrapractice variation (within a single physician between the years) was explained better than the interphysician (between physicians). Health services with high explained variation were blood tests characterised by both low intrapractice variation (Rs=-0.65, p value=0.005) and high referral rates (Rs=0.46, p value=0.06).

CONCLUSION

Over 70% of MPV is not explained by the patient, clinic and physician demographic and professional characteristics. Future research should focus on the fraction of MPV that is explained by the physicians' psychological characteristics, and thus potentially identify psychological targets for behavioural modifications aimed at reducing MPV.

The variability of diagnosed migraine epidemiology amongst different municipalities in southern Israel

BACKGROUND

Appropriate and timely diagnosis is one of the most important milestones in effective migraine care and is affected by public awareness, access to medical care, health care systems, and physicians' knowledge. We assessed the variability in migraine diagnosis rates in different communities under universal national health coverage in Israel.

METHODS

In this population-based retrospective, observational, cohort study, adult (≥18 years) migraine patients were identified in the computerized database of the southern district of the Clalit Health Services Health Maintenance Organization (HMO) based on recorded diagnosis and/or purchase of specific anti-migraine acute medication (triptans). Migraine prevalence in 2018 was calculated in the entire study population and in different municipalities. We utilized a standardized (age and gender) mortality ratio (SMR) approach for comparison among the municipalities.

RESULTS

In 2018, a total of 29,938 migraine patients were identified out of 391,528 adult HMO members, with an overall prevalence (per 10,000) of migraine of 764.64 (7.65%), 1143.34 (11.43%) for women, and 374.97 (3.75%) for men. Among the municipalities, adjusted prevalence (per 10,000) ranged from 386.15 (3.86%) to 1320.60 (13.21%). The female-to-male ratio ranged from 1.8:1 to 5.1:1. Prevalence rates were positively associated with the socioeconomic status of the municipalities (Spearman rho = 0.472, P = 0.031).

CONCLUSIONS

High variability in the prevalence of diagnosed migraine suggests underdiagnosis. Resources for awareness and educational programs should be directed to low diagnosed prevalence communities.

Migraine epidemiology and comorbidities in Southern Israel: a clinical database study in a universal health coverage setting

BACKGROUND

Understanding migraine epidemiology and its burden is crucial for planning health policies and interventions at the local level as well as at the global level. National policies in Israel rely on global estimations and not on local data since local epidemiologic studies had not previously been performed. In this study, we evaluated the epidemiology of migraine in the southern district of Israel using the electronic medical records database of the largest Israeli health maintenance organization (HMO).

METHODS

In this population-based, retrospective, observational cohort study, adult migraine patients were identified in the computerized database of the southern district of the Clalit Health Services HMO (total population, 0.75 million). Patients were identified based on recorded diagnosis (International Classification of Diseases, Ninth Revision) and/or claims for specific anti-migraine medication (triptans) between 2000 and 2018. A 1:2 age-, gender-, and primary care clinic-matched control group was used for evaluation of comorbidities.

RESULTS

In 2018, a total of 29,938 patients with migraine were identified out of 391,528 adult HMO members. Most of the patients were women (75.8%), and the mean ± standard deviation age at diagnosis was 36.94 ± 13.61 years. The overall prevalence of migraine (per 10,000) was 764.64 (7.65%), 1143.34 (11.43%) for women and 374.97 (3.75%) for men. The highest prevalence was observed in patients aged 50 to 60 years and 40 to 50 years (1143.98 [11.44%] and 1019.36 [10.19%], respectively), and the lowest prevalence was among patients aged 18 to 30 years and > 70 years (433.45 [4.33%] and 398.49 [3.98%], respectively).

CONCLUSIONS

This is the first large-scale epidemiologic study of migraine prevalence in Israel. Compared to international estimations, migraine appears to be underdiagnosed in the southern district of Israel.

Patterns of black and white hysterectomy incidence among reproductive aged women

OBJECTIVE

To investigate the intersection of race and economic context in treatment with hysterectomy among reproductive aged women with noncancerous gynecologic conditions.

DATA SOURCES

We combined administrative billing records of inpatient and outpatient hysterectomy procedures (N = 28 301) occurring in North Carolina between 2011 and 2014 with census data to calculate county-level hysterectomy rates.

STUDY DESIGN

Spatial analysis techniques examined the distribution of black and white hysterectomy rates across counties, and county-level black and white rate differences were compared across economic contexts.

DATA COLLECTION/EXTRACTION

We restricted to those of premenopausal age identifying as non-Hispanic black or white, undergoing hysterectomy for nonemergent causes (N = 28 301 procedures).

PRINCIPAL FINDINGS

County-level hysterectomy rates were spatially patterned (Moran's I, P < .05) and similarly so for black and white women (LISA, P < .005). The black-white difference in hysterectomy rates was the largest in the high economic tier counties (22/10 000 person-years [PY], P < .05) and smallest in the mid and low economic tier counties (11/10 000 PY, P > .05 and 10/10 000 PY, P > .05, respectively).

CONCLUSION

Socioeconomic context is important to understand, particularly for black-white disparities in hysterectomy. Efforts should be made to understand the causes of higher rates of hysterectomy among blacks than whites, especially in counties in the highest economic tier.

Medical Practice Variation Among Primary Care Physicians: 1 Decade, 14 Health Services, and 3,238,498 Patient-Years

PURPOSE

Variation in medical practice is associated with poorer health outcomes, increased costs, disparities in care, and increased burden on the public health system. In the present study, we sought to describe and assess inter- and intra-primary care physician variation, adjusted for patient and clinic characteristics, over a decade of practice and across a broad range of health services.

METHODS

We assessed practice patterns of 251 primary care physicians in southern Israel. For each of 14 health services (imaging tests, cardiac tests, laboratory tests, and specialist visits) we described interphysician and intraphysician variation, adjusted for patient case mix and clinic characteristics, using the coefficient of variation. The adjusted rates were assessed by generalized linear negative-binomial mixed models.

RESULTS

The variation between physicians was on average 3-fold greater than the variation of individual physician practice over the years. Services with low utilization were associated with greater inter- and intraphysician variation: r_s = (-0.58), P = .03 and r_s = (-0.39), P = .17, respectively. In addition, physician utilization ranks averaged over all health services were consistent across the 14 health services (intraclass correlation coefficient, 0.94; 95% CI, 0.93-0.95).

CONCLUSIONS

Our results show greater variation in practice patterns between physicians than for individual physicians over the years. It appears that the variation remains high even after adjustment for patient and clinic characteristics and that the individual physician utilization patterns are stable across health services. We propose that personal behavioral characteristics of medical practitioners might explain this variation.

Determinants of Medical Practice Variation Among Primary Care Physicians: Protocol for a Three Phase Study

BACKGROUND

One of the greatest challenges of modern health systems is the choice and use of resources needed to diagnose and treat patients. Medical practice variation (MPV) is a broad term which entails the differences between health care providers inclusive of both the overuse and underuse. In this paper, we describe a 3-phase research protocol examining MPV in primary care.

OBJECTIVE

We aim to identify the potential targets for behavioral modification interventions to reduce the variation in practice patterns and thus improve health care, decrease costs, and prevent disparities in care.

METHODS

The first phase will delineate the variation in primary care practice over a wide range of services and long follow-up period (2003-2017), the second will examine the 3 determinants of variation (ie, patient, physician, and clinic characteristics), and attempt to derive the unexplained variance. In the third phase, we will assess a novel component that might contribute to the previously unexplained variance - the physicians' personal behavioral characteristics (such as risk aversion, fear of malpractice, stress from uncertainty, empathy, and burnout).

RESULTS

This work was supported by the research grant from Israel National Institute for Health Policy Research (Grant No. 2014/134). Soroka University Medical Center Institutional Ethics Committee has approved the updated version of the study protocol (SOR-14-0063) in February 2019. All relevant data for phases 1 and 2, including patient, physician, and clinic, were collected from the Clalit Health Services data set in 2019 and are currently being analyzed. The evaluation of the individual physician characteristics (eg, risk aversion) by the face-to-face questionnaires was started on 2018 and remains in progress. We intend to publish the results during 2020-2021.

CONCLUSIONS

Based on the results of our study, we aim to propose a list of potential targets for focused behavioral intervention. Identifying new targets for such an intervention can potentially lead to a decrease in the unwarranted variation in the medical practice. We suggest that such an intervention will result in optimization of the health system, improvement of health outcomes, reduction of disparities in care and savings in cost.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/18673.

Double disparities in the health care for people with schizophrenia of an ethnic-national minority

BACKGROUND

Studies have shown health care disparities among persons of minority status, including in countries with universal health care. Yet, a dearth of studies have addressed disparities resulting from the combined effect of two minority status groups: severe mental illness and ethnic-national sector filiation. This study aimed to compare the differential health care of Jewish- and Arab-Israelis with schizophrenia in a country with a universal health insurance.

METHOD

This study builds on a large case-control epidemiological sample (N = 50,499) of Jewish- (92.9%) and Arab-Israelis (7.1%) service users with (n = 16,833) and without schizophrenia (n = 33,666). Health services records were collected in the years 2000-2009. Diabetes and cardiovascular disease (CVD) served as sentinel diseases. We compared annual number of LDL tests and visits to specialists in the entire sample, Hemoglobin-A1C test among people diagnosed with diabetes, and cardiac surgical interventions for those diagnosed with CVD.

RESULTS

Service users with schizophrenia were less likely to meet identical indexes of care as their study counterparts: 95% of cholesterol tests (p < .001), and 92% visits to specialists (p < .001). These differences were greater among Arab- compared to Jewish-Israelis. Annual frequency of Hemoglobin-A1C test among people diagnosed with diabetes was lower (94%) in people with schizophrenia (p < 0.01), but no ethnic-national differences were identified. Among service users with CVD less surgical interventions were done in people with schizophrenia (70%) compared to their counterparts, with no ethnic-national disparities.

CONCLUSIONS

In Israel, service users with schizophrenia fail to receive equitable levels of medical and cardiac surgical care for CVD and regular laboratory tests for diabetes. Although disparities in some health indicators were enhanced among Arab-Israelis, schizophrenia was a greater source of disparities than ethnic-national filiation.