The Effect of Geographic Units of Analysis on Measuring Geographic Variation in Medical Services Utilization

Healthcare service use and medical outcomes of tracheostomy-dependent children: a nationwide study

BACKGROUND

Despite the rising trend of tracheostomies in children, there is a lack of comprehensive resources for families to navigate the challenges of living with a tracheostomy, emphasising the need for evidence-based support in understanding postoperative care and long-term adjustments. This study aimed to examine the pattern of using healthcare services and nationwide medical outcomes in children who underwent a tracheotomy before the age of 2 years.

METHODS

This retrospective study used the National Health Insurance System database from 2008 to 2016 and included all children codified with tracheotomy procedure codes before their second birthday. Healthcare utilisation, such as medical costs, number of hospital visits, home healthcare nursing and medical diagnoses on readmission, in the first 2 years after tracheotomy was evaluated. Multivariable logistic regression analysis was used to determine the factors affecting mortality.

RESULTS

In total, 813 patients were included in this study. Their use of healthcare services and the accompanying expenses were higher than the national medians for similar age groups; however, both metrics decreased in the second year. The major causes of admission within 2 years of surgery were respiratory and neurological diseases. The mortality rate within 2 years was 37.8%. Higher risks of mortality were associated with having two or more complex chronic conditions. Use of home healthcare nursing services was associated with a lower mortality risk.

CONCLUSION

Paediatric patients with more complex chronic conditions tended to have higher mortality rates within 2 years after surgery. However, receiving home healthcare nursing was significantly associated with a reduced risk of death. Many causes of hospitalisation may be preventable with education and supportive care. Therefore, further research for establishing an integrated care system for these patients and their caregivers is required.

Geographic Distribution of Central Nervous System Rehabilitation Treatment in Korea and Its Associated Factors

BACKGROUND

Health disparity is defined as a difference in the accessibility of medical resources among regions or other factors. In South Korea, there might be a disparity because of the low proportion of public medical institutions. This study aimed to investigate the geographic distribution of rehabilitation treatment and examine the factors associated with the rates of rehabilitation treatment in Korea.

METHODS

We used administrative claims data in 2007, 2012, and 2017 from the National Health Insurance Database in Korea. We defined physical therapy and occupational therapy as rehabilitation treatments and analyzed the rate of rehabilitation treatments for administrative districts in 2007, 2012, and 2017. Interdecile range and coefficient of variation were used to investigate the geographic distribution of rehabilitation treatment over time. We applied multiple random intercept negative binomial regression to examine the factors associated with rehabilitation treatment. A total of 28,319,614 inpatient and outpatient claims were submitted for 874 hospitals that provided rehabilitation treatment in 2007, 2012, and 2017.

RESULTS

The increase in the mean rates of physical therapy inpatients and outpatients was greater than those for occupational therapy inpatients and outpatients from 2007 to 2017. Both physical therapy and occupational therapy were concentrated in the Seoul Capital Area and other large urban areas. More than 30% of the districts received no rehabilitation treatment. The interdecile range and coefficient of variation for physical therapy declined more than those for occupational therapy from 2007 to 2017. The deprivation index was negatively correlated with physical therapy inpatients, physical therapy outpatients, occupational therapy inpatients, and occupational therapy outpatients. Furthermore, a 1-unit increase in the number of hospital beds per 1,000 people was associated with 1.42 times higher physical therapy inpatient, 1.44 times higher physical therapy outpatient, 2.14 times higher occupational therapy inpatient, and 3.30 times higher occupational therapy outpatient treatment.

CONCLUSION

To reduce the geographic inequality in rehabilitation treatment, it is necessary to narrow the gap between the supply and demand of rehabilitation services. Providing incentives or direct provisions from the government might be an alternative.

Defining Referral Regions for Inpatient Trauma Care: The Utility of a Novel Geographic Definition

INTRODUCTION

Geographic variation is an inherent feature of the US health system. Despite efforts to account for geographic variation in trauma system strengthening, it remains unclear how trauma "regions" should be defined. The objective of this study is to evaluate the utility of a novel definition of Trauma Referral Regions (TRR) for assessing geographic variation in inpatient trauma across the age span of hospitalized trauma patients.

METHODS

Using 2016-2017 State Inpatient Databases, we assessed the extent of geographic variability in three common metrics of hospital use (localization index, market share index, net patient flow) among TRRs and, as a comparison, trauma regions alternatively defined based on Hospital Referral Regions, Hospital Service Areas, and counties.

RESULTS

A total of 860,593 admissions from 102 TRRs, 127 Hospital Referral Regions, 884 Hospital Service Areas, and 583 counties were included. Consistent with expectations for distinct trauma regions, TRR presented with high average localization indices (mean [standard deviation]: 83.4 [11.7%]), low market share indices (mean [standard deviation]: 11.9 [7.0%]), and net patient flows close to 1.00. Similar results were found among stratified pediatric, adult, and older adult patients. Associations between TRRs and variations in important demographic features (e.g., travel time by road to the nearest Level I or II Trauma Center) suggest that while indicative of standalone trauma regions, TRRs are also able to simultaneously capture critical variations in regional trauma care.

CONCLUSIONS

TRRs offer a standalone set of geographic regions with minimal variation in common metrics of hospital use, minimal geographic clustering, and preserved associations with important demographic factors. They provide a needed, valid means of assessing geographic variation among trauma systems.

Regional Variation of Hospitalization Rates for Asthma in Korea: Association with Ambient Carbon Monoxide and Health Care Supply

This study was performed to investigate the relationship between the hospitalization rate for asthma and the ambient carbon monoxide (CO) by examining regional variation of the hospitalization rates for asthma in Korea and its factors. The hospital inpatient claims for asthma were acquired from the National Health Insurance database in 2015. A multivariate linear regression was performed with the hospitalization rate for asthma as a dependent variable. The annual ambient concentration of CO showed a negative association with the hospitalization rates for asthma while that of sulfur dioxide showed a positive association. The number of primary care physicians showed a negative association with the hospitalization rates for asthma while the number of beds in hospitals with less than 300 beds showed a positive association. The negative association of the ambient concentration of CO with the hospitalization rates for asthma showed results upon further investigation.

Healthcare utilization among children and young people with life-limiting conditions: Exploring palliative care needs using National Health Insurance claims data

Paediatric palliative care (PPC) is regarded as standard care for children and young people (CYP) with life-limiting conditions (LLCs). There is a lack of knowledge about the rate of CYP with LLCs, hampering the development of PPC. This retrospective study aimed to examine population-based statistics of South Korean CYP with LLCs and the pattern of healthcare use and costs in their last year of life, analysing the National Health Insurance Service claims database for the period 2013-2015. In 2015, the number of CYP (≤24 years old) living with LLCs was 133,177, with those who died accounting for 1,032. Prevalence of LLC and mortality rate per 100,000 were highest among under-1-age group (2,151.7 and 82.7, respectively). In the last year of life, 91.8% of deceased CYP with LLCs were hospitalized at least once and the average length of stay was 101.2 days (standard deviation = 104.1). Deceased CYP with cancer spent more on healthcare than non-cancer CYP (64,266 vs. 40,694 US dollar, p < 0.001). The average relevance index for CYP death related to LLCs was 55.9%. Our results provide baseline information on healthcare utilization and expenditure among CYP with LLCs, which is crucial data for designing evidence-based PPC policy and services.

Factors associated with the rates of coronary artery bypass graft and percutaneous coronary intervention

BACKGROUND

Korea has seen a rapid increase in the use of percutaneous coronary intervention (PCI) with the ratio of PCI to coronary artery bypass graft (CABG) the highest in the world. This study was performed to examine the factors associated with the rates of CABG and PCI.

METHODS

The data were acquired from the National Health Insurance database in Korea in 2013. We calculated the age-sex standardized rates of CABG and PCI. We examined the factors associated with the CABG and PCI rates by performing a regression analysis.

RESULTS

The rate of CABG showed a negative association with the deprivation index score, and other factors, such as the number of providers or hospital beds, did not show any significant association with the CABG rate. The rate of PCI had a strong negative association with the number of cardiothoracic surgeons and a strong positive association with the number of hospital beds.

CONCLUSIONS

The positive association between the PCI rate and the number of hospital beds suggests that the use of PCI may be driven by the supply of beds, and the inverse association between the PCI rate and the number of cardiothoracic surgeons indicates the overuse of PCI due to lack of the providers of CABG. Policy measures should be taken to optimize the use of revascularization procedures, the choice of which should primarily be based on the patient's need.

Geographic variation and factors associated with rates of knee arthroplasty in Korea-a population based ecological study

Background

The recent increase in knee arthroplasty (KA) use in Korea is among the highest in the world. The rapid increase in KA use suggests that the KA use in Korea could have been affected by medically unjustifiable factors. This study aimed to examine the geographic variation in the rate of KA and its associated factors in Korea.

Methods

We used the data from the National Health Insurance in Korea in 2013, from which a total of 67,086 claims for KA were obtained. We calculated the age-sex-standardized KA rates of the entire population and the crude rates of the age groups 0–64 and 65 and over in 251 districts. We assessed the geographic variation of the KA rates and examined the associated factors with a multivariate linear regression with the KA rate as a dependent variable.

Results

The overall rate of KA in Korea was 132.7 per 100,000 persons. The rates of KA showed a four-fold variation. The deprivation index score and the number of beds in the small to medium sized hospitals showed a positive association with the rates of KA while the number of orthopedic surgeons showed a negative association.

Conclusions

Korea has been experiencing a rapid increase in the use of KA for the last decade or so, which was most prominent among the elderly population aged 65 and older. Our results suggest that the higher rate of KA is strongly related to a higher supply of beds and the socioeconomically deprived conditions. Considering that the decision concerning KA has room for discretion and also affects a considerable portion of health care expenditures, the use of KA should be thoroughly monitored with more emphasis on standardization in the decision making process and preventive measures that can lessen the need for KA.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2766-y) contains supplementary material, which is available to authorized users.

An ecological study of geographic variation and factors associated with cesarean section rates in South Korea

BACKGROUND

Korea is in a condition where the impact of patient and supplier factors on cesarean section rates can be clearly described. The cesarean section rates in Korea are among the highest in the world while the number of obstetricians is decreasing sharply. This study aimed to investigate the geographic variation in cesarean section rates in Korea and its factors.

METHODS

The data were obtained from the National Health Insurance database in Korea in 2013. We calculated the age-standardized and crude cesarean section rates of 251 districts in Korea and variation statistics. A linear regression analysis was performed to determine factors for cesarean section rates.

RESULTS

The overall cesarean section rate in Korea was 364.6 cases per 1000 live births. The deprivation index score was strongly associated with the increase in the cesarean section rate while the density of hospital obstetricians and hospital beds showed a negative association. Average maternal age and total fertility rate showed a negative relationship with the cesarean section rate.

CONCLUSIONS

Korea is suffering from a continuing decrease in obstetricians. Our study shows that this decline has more of an effect on mothers in the disadvantaged areas. Securing equal access to obstetric care among areas is necessary, and measures to encourage obstetricians and mothers not to opt for cesarean section are required.

Hospitalizations for ambulatory care sensitive conditions as an indicator of access to primary care and excess of bed supply

BACKGROUND

Ambulatory care sensitive conditions (ACSC) hospitalization is a widely accepted measure of the access to primary care. However, given its discretionary characteristics, the ACSC hospitalization can be a measure reflecting the influence of hospital bed supply. In Korea, where the quality of primary care and oversupply of hospital beds are coexistent concerns, ACSC hospitalization can be used to examine the impact of both factors. This study was performed to investigate the ACSC hospitalization rate as a measure of the hospital bed supply as well as access to primary care.

METHODS

Data were obtained from the National Health Insurance Database for 2015. We calculated the age-sex standardized hospitalization rates for ACSC in the total population and crude rates of ACSC hospitalization for three different age groups in 252 districts in Korea. We calculated the variation statistics of ACSC hospitalization rates, and we estimated a linear regression model to investigate the factors for ACSC hospitalization.

RESULTS

There was a very high geographic variation in ACSC hospitalization rates. Higher density of primary care physicians was associated with a decreased ACSC hospitalization rate while a higher density of hospital beds in small to medium sized hospitals was associated with an increased rate. The deprivation index score had a strongly positive association with the ACSC hospitalization rates.

CONCLUSION

ACSC hospitalization, while being a negative index of primary care access, can also be a measure indicating the impact of the hospital bed supply, and it is still a valid measure of the disparity of health care, the original motivation for this topic.

Regional Differences in Years of Life Lost in Korea from 1997 to 2015

BACKGROUND

Reducing the gaps in health inequality at a regional level and improving health equity have been emphasized in Korea, it is essential to accurately measure the burden of disease by region. This study aimed to estimate years of life lost (YLLs) in 17 Si and Do of Korea from 1997 to 2015 and determine the trends of regional differences in health status and disease structure.

METHODS

YLL was calculated by subtracting the age at death from the life expectancy. Data on the region, gender, and age-stratified cause-specific death were obtained from the Korean Statistical Information Service of Statistics Korea.

RESULTS

Age-standardized YLLs per 100,000 population decreased by year in all regions from 1997 to 2015 by 27.4% (27.5% for men; 27.2% for women). Despite the decline in YLLs, the regions with the highest and lowest YLLs did not change between 1997 and 2015. The diseases showing regional differences were caused by injury, often classified as avoidable mortality. We also confirmed that YLLs were higher in the regions with a higher deprivation index.

CONCLUSION

The present study identified that YLLs differed by regions in Korea with specific causes. The findings of this study can be used by decision-makers to prioritize the reduction of regional gaps in premature deaths.

A spatial analysis of geographic variation and factors associated with hospitalization for bacterial pneumonia in Korea

BACKGROUND

The incidence of pneumonia in Korea started to increase in the 1990's after a period of decrease and stabilization, and the mortality and hospitalization rates for pneumonia in Korea are alarmingly high. This study was performed to examine geographic variation and factors associated with hospitalization for bacterial pneumonia in Korea.

METHODS

Data were acquired from the inpatient claims of the 2015 period of the National Health Insurance Service. The age- and sex-standardized hospitalization rates for bacterial pneumonia were calculated for three age groups. Geographic variation was measured with the coefficient of variation, the ratio of the 90th to the 10th percentile of the distribution of rates, and the systematic component of variation. Considering the results of Moran's I statistic which suggested spatial autocorrelation, we estimated spatial regression models using spatial error models.

RESULTS

The hospitalization rate for bacterial pneumonia was 79.1 per 10,000 population, and the rate was the highest in the age group 0-14 at 325.3, and it was 161.5 among the elderly. The geographic variation statistics showed high variation with the coefficient variation at 0.6. The deprivation score showed positive associations, and the number of primary care physicians had a negative association with the hospitalization rates across all age groups but the age group 0-14. The number of beds in hospitals with less than 300 beds had a positive association with the hospitalization rates for bacterial pneumonia, and the impact was the strongest in the age group 0-14.

CONCLUSIONS

The present study shows that pneumonia can be a major public health issue even in a developed country. Socioeconomic conditions can still be a concern for pneumonia in developed countries, and the role of primary care physicians in preventing hospitalization for bacterial pneumonia needs to be recognized. Most of all, the strong impact of hospital beds on the hospitalization rates for pneumonia, especially for the children, should be addressed. High disease burden of pneumonia in Korea can partly be attributable to oversupply of hospital beds. These factors should be taken into consideration in establishing policy measures for the rise in pneumonia.

A framework for the identification and classification of homogeneous socioeconomic areas in the analysis of health care variation

BACKGROUND

Detecting the variation of health indicators across similar areas or peer geographies is often useful if the spatial units are socially and economically meaningful, so that there is a degree of homogeneity in each unit. Indices are frequently constructed to generate summaries of socioeconomic status or other measures in geographic small areas. Larger areas may be built to be homogenous using regionalization algorithms. However, there are no explicit guidelines in the literature for the grouping of peer geographies based on measures such as area level socioeconomic indices. Moreover, the use of an index score becomes less meaningful as the size of an area increases. This paper introduces an easy to use statistical framework for the identification and classification of homogeneous areas. We propose the Homogeneity and Location indices to measure the concentration and central value respectively of an areas' socioeconomic distribution. We also provide a transparent set of criteria that a researcher can follow to establish whether a set of proposed geographies are acceptably homogeneous or need further refining.

RESULTS

We applied our framework to assess the socioeconomic homogeneity of the commonly used SA3 Australian census geography. These results showed that almost 60% of the SA3 census units are likely to be socioeconomically heterogeneous and hence inappropriate for presenting area level socioeconomic disadvantage. We also showed that the Location Index is a more robust descriptive measure of the distribution compared to other measures of central tendency. Finally, the methodology proposed was used to analyse the age-standardized variation of GP attenders in a metropolitan area. The results suggest that very high GP attenders (20+ visits) live in SA3s with the most socioeconomic disadvantage. The findings revealed that households with low income and families with children and jobless parents are the major drivers for discerning disadvantaged communities.

CONCLUSION

Reporting indicators rates for geographies grouped according to similarity may be useful for the analysis of geographic variation. The use of a framework for the identification of meaningful peer geographies would be beneficial to health planners and policy makers by providing realistic and valid peer group geographies.

Epidemiology of pathogens and antimicrobial resistanceof catheter-associated urinary tract infections in intensivecare units: A systematic review and meta-analysis

BACKGROUND

In the intensive care unit (ICU), catheter-associated urinary tract infection (CAUTI) is the most common urinary tract infection. Nevertheless, there is no systematic review to investigate the epidemiology of pathogens and antimicrobial resistance of CAUTIs in ICUs.

METHODS

Eight electronic databases were searched for eligible studies. A meta-analysis was performed to calculate the CAUTI incidence per 1,000 catheter days, the proportion of pathogen distribution, and the resistance rate with R3.3.2 software.

RESULTS

Seventy-five studies were included. The total weighted CAUTI incidence per 1,000 catheter days was 7.78. Gram-negative bacteria (47.46%), fungi (27.81%), and gram-positive bacteria (19.06%) were isolated. Candida spp (27.4%), Escherichia spp (23.41%), and Enterococcus spp (15.0%) were the most frequent pathogens. Candida albicans, Candida tropicalis, and Candida glabrata were generally resistant to itraconazole, with resistance rates of 42.5%, 53.0%, and 59.7%, respectively. Escherichia spp displayed high rates of resistance to ampicillin (87.3%), ciprofloxacin (71.7%), and norfloxacin (71.2%). Enterococcus spp showed high rates of resistance to erythromycin (83.9%), penicillin (76.7%), and levofloxacin (73.8%).

CONCLUSIONS

In ICUs, the CAUTI incidence per 1,000 catheter days is high. CAUTIs were mainly caused by gram-negative bacteria that were resistant to common antibiotics. There is a pressing demand for future research into CAUTI, including effective prevention, an understanding of antimicrobial resistance mechanisms, and development of new antibiotics for patient safety.

Regional variation in healthcare spending and mortality among senior high-cost healthcare users in Ontario, Canada: a retrospective matched cohort study

Background

Senior high cost health care users (HCU) are a priority for many governments. Little research has addressed regional variation of HCU incidence and outcomes, especially among incident HCU. This study describes the regional variation in healthcare costs and mortality across Ontario’s health planning districts [Local Health Integration Networks (LHIN)] among senior incident HCU and non-HCU and explores the relationship between healthcare spending and mortality.

Methods

We conducted a retrospective population-based matched cohort study of incident senior HCU defined as Ontarians aged ≥66 years in the top 5% most costly healthcare users in fiscal year (FY) 2013. We matched HCU to non-HCU (1:3) based on age, sex and LHIN. Primary outcomes were LHIN-based variation in costs (total and 12 cost components) and mortality during FY2013 as measured by variance estimates derived from multi-level models. Outcomes were risk-adjusted for age, sex, ADGs, and low-income status. In a cost-mortality analysis by LHIN, risk-adjusted random effects for total costs and mortality were graphically presented together in a cost-mortality plane to identify low and high performers.

Results

We studied 175,847 incident HCU and 527,541 matched non-HCU. On average, 94 out of 1000 seniors per LHIN were HCU (CV = 4.6%). The mean total costs for HCU in FY2013 were 12 times higher that of non-HCU ($29,779 vs. $2472 respectively), whereas all-cause mortality was 13.6 times greater (103.9 vs. 7.5 per 1000 seniors).

Regional variation in costs and mortality was lower in senior HCU compared with non-HCU. We identified greater variability in accessing the healthcare system, but, once the patient entered the system, variation in costs was low. The traditional drivers of costs and mortality that we adjusted for played little role in driving the observed variation in HCUs’ outcomes. We identified LHINs that had high mortality rates despite elevated healthcare expenditures and those that achieved lower mortality at lower costs. Some LHINs achieved low mortality at excessively high costs.

Conclusions

Risk-adjusted allocation of healthcare resources to seniors in Ontario is overall similar across health districts, more so for HCU than non-HCU. Identified important variation in the cost-mortality relationship across LHINs needs to be further explored.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0952-7) contains supplementary material, which is available to authorized users.

Geographic variation in health insurance benefits in Qianjiang District, China: a cross-sectional study

BACKGROUND

Health insurance contributes to reducing the economic burden of disease and improving access to healthcare. In 2016, the Chinese government announced the integration of the New Cooperative Medical Scheme (NCMS) and Urban Resident Basic Medical Insurance (URBMI) to reduce system segmentation. Nevertheless, it was unclear whether there would be any geographic variation in health insurance benefits if the two types of insurance were integrated. The aim of this study was to identify the potential geographic variation in health insurance benefits and the related contributing factors.

METHODS

This cross-sectional study was carried out in Qianjiang District, where the NCMS and URBMI were integrated into Urban and Rural Resident Basic Medical Insurance Scheme (URRBMI) in 2010. All beneficiaries under the URRBMI were hospitalized at least once in 2013, totaling 445,254 persons and 65,877 person-times, were included in this study. Town-level data on health insurance benefits, healthcare utilization, and socioeconomic and geographical characteristics were collected through health insurance system, self-report questionnaires, and the 2014 Statistical Yearbook of Qianjiang District. A simplified Theil index at town level was calculated to measure geographic variation in health insurance benefits. Colored maps were created to visualize the variation in geographic distribution of benefits. The effects of healthcare utilization and socioeconomic and geographical characteristics on geographic variation in health insurance benefits were estimated with a multiple linear regression analysis.

RESULTS

Different Theil index values were calculated for different towns, and the Theil index values for compensation by person-times and amount were 2.5028 and 1.8394 in primary healthcare institutions and 1.1466 and 0.9204 in secondary healthcare institutions. Healthcare-seeking behavior and economic factors were positively associated with health insurance benefits in compensation by person-times significantly, meanwhile, geographical accessibility and economic factors had positive effects (p < 0.05).

CONCLUSIONS

The geographic variation in health insurance benefits widely existed in Qianjiang District and the distribution of health insurance benefits for insured inpatients in primary healthcare institutions was distinctly different from that in secondary healthcare institutions. When combining the NRCM and URMIS in China, the geographical accessibility, healthcare-seeking behavior and economic factors required significant attention.

Senior high-cost healthcare users' resource utilization and outcomes: a protocol of a retrospective matched cohort study in Canada

INTRODUCTION

Senior high-cost users (HCUs) are estimated to represent 60% of all HCUs in Ontario, Canada's most populous province. To improve our understanding of individual and health system characteristics related to senior HCUs, we will examine incident senior HCUs to determine their incremental healthcare utilisation and costs, characteristics of index hospitalisation episodes, mortality and their regional variation across Ontario.

METHODS AND ANALYSIS

A retrospective, population-based cohort study using administrative healthcare records will be used. Incident senior HCUs will be defined as Ontarians aged ≥66 years who were in the top 5% of healthcare cost users during fiscal year 2013 but not during fiscal year 2012. Each HCU will be matched to three non-HCUs by age, sex and health planning region. Incremental healthcare use and costs will be determined using the method of recycled predictions. We will apply multivariable logistic regression to determine patient and health service factors associated with index hospitalisation and inhospital mortality during the incident year. The most common causes of admission will be identified and contrasted with the most expensive hospitalised conditions. We will also calculate the ratio of inpatient costs incurred through admissions of ambulatory care sensitive conditions to the total inpatient expenditures. The magnitude of variation in costs and health service utilisation will be established by calculating the extremal quotient, the coefficient of variation and the Gini mean difference for estimates obtained through multilevel regression analyses.

ETHICS AND DISSEMINATION

This study has been approved by Hamilton Integrated Research Ethics Board (ID#1715-C). The results of the study will be distributed through peer-reviewed journals. They also will be disseminated at research events in academic settings, national and international conferences as well as with presentations to provincial health authorities.

Evaluation of Geographic Indices Describing Health Care Utilization

Objectives

The accurate measurement of geographic patterns of health care utilization is a prerequisite for the study of geographic variations in health care utilization. While several measures have been developed to measure how accurately geographic units reflect the health care utilization patterns of residents, they have been only applied to hospitalization and need further evaluation. This study aimed to evaluate geographic indices describing health care utilization.

Methods

We measured the utilization rate and four health care utilization indices (localization index, outflow index, inflow index, and net patient flow) for eight major procedures (coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, surgery after hip fracture, knee replacement surgery, caesarean sections, hysterectomy, computed tomography scans, and magnetic resonance imaging scans) according to three levels of geographic units in Korea. Data were obtained from the National Health Insurance database in Korea. We evaluated the associations among the health care utilization indices and the utilization rates.

Results

In higher-level geographic units, the localization index tended to be high, while the inflow index and outflow index were lower. The indices showed different patterns depending on the procedure. A strong negative correlation between the localization index and the outflow index was observed for all procedures. Net patient flow showed a moderate positive correlation with the localization index and the inflow index.

Conclusions

Health care utilization indices can be used as a proxy to describe the utilization pattern of a procedure in a geographic unit.