Hyeong Jun Ahn

Predictors of Outcome Following Hip Fracture Rehabilitation

To determine the potential predictors of functional outcome after hip fracture rehabilitation in a large acute inpatient rehabilitation facility.

Arsenic in Drinking Water and Stroke Hospitalizations in Michigan

Background and Purpose— Mechanistic and human studies suggest a role for arsenic in ischemic stroke; however, risks from chronic, low-level exposures are uncertain and US studies are lacking. The objective was to investigate the association between low-level arsenic exposure in drinking water and ischemic stroke hospital admissions in Michigan. Methods— Ischemic stroke hospital admissions among those aged ≥45 years were identified (1994 to 2006). Population-weighted average arsenic concentrations were estimated for each Michigan county (n=83) and for zip codes in Genesee County (n=27) where there is greater variation in arsenic concentrations. US Census data provided age- and sex-specific population counts and other county- and zip code-level variables (race, income), which were adjusted for in multilevel negative binomial regression models of arsenic and stroke admissions. Hospital admissions for duodenal ulcer and hernia, not hypothesized to be associated with arsenic, were also evaluated. Results— Adjusted county-level analyses suggested a relationship between arsenic and ischemic stroke hospital admissions, although similar associations were observed for duodenal ulcer and hernia. In zip code-level analysis, arsenic was associated with an increased risk of stroke admission (relative risk, 1.03; 95% CI, 1.01 to 1.05 per &mgr;g/L increase in arsenic) after adjustment for confounders, and null or negative associations were found between arsenic and nonvascular outcomes. Conclusions— Findings from this study suggest that exposure to even low levels of arsenic in drinking water may be associated with a higher risk of incident stroke. Given the ecological nature of the analysis, further epidemiological study with individual-level data on arsenic exposure and incident stroke is warranted.

Lynch Syndrome in patients with clear cell and endometrioid cancers of the ovary

OBJECTIVE Patients with Lynch Syndrome are at an increased risk for a variety of malignancies, including ovarian cancer. Ovarian cancers associated with Lynch Syndrome are predominantly clear cell or endometrioid in histology. Lynch Syndrome is characterized by germline mutations in mismatch repair (MMR) genes. The current study aims to assess the prevalence of loss of MMR expression in patients with endometrioid and clear cell ovarian carcinoma. METHODS A retrospective review identified 90 patients with endometrioid and/or clear cell carcinomas. Slides made from tumor tissue microarray blocks were evaluated using immunohistochemical stains with antibodies against MLH1, PMS2, MSH2, and MSH6. Statistical analysis was performed. RESULTS Seven of the 90 cases (7.8%) had loss of MMR expression. The mean age of patients with loss of MMR expression (47 years) was significantly younger than those with retained MMR expression (p=0.014). Loss of MMR expression was present in 20% of patients under the age of 53 with clear cell or endometrioid cancers. Genetic studies found that 3 of the 5 patients with loss of MMR expression carried mutations consistent with Lynch Syndrome; acquired hypermethylation of MLH1 was noted in one patient. Six of 7 patients (86%) whose tumors lacked MMR expression had synchronous or metachronous primary malignancies, a significantly greater prevalence than those with retained MMR expression (p<0.001). CONCLUSION Patients under the age of 53 with clear cell or endometrioid ovarian carcinomas are at a clinically significant risk for loss of MMR expression and Lynch Syndrome; routine screening with immunohistochemical staining should be considered.

Comparison of potentially preventable hospitalizations related to diabetes among Native Hawaiian, Chinese, Filipino, and Japanese elderly compared with whites, Hawai'i, December 2006-December 2010.

Introduction Approximately 25% of individuals aged 65 years or older in the United States have diabetes mellitus. Diabetes rates in this age group are higher for Asian American and Pacific Islanders (AA/PI) than for whites. We examined racial/ethnic differences in diabetes-related potentially preventable hospitalizations (DRPH) among people aged 65 years or older for Japanese, Chinese, Filipinos, Native Hawaiians, and whites. Methods Discharge data for hospitalizations in Hawai‘i for people aged 65 years or older from December 2006 through December 2010 were compared. Annual rates of DRPH by patient were calculated for each racial/ethnic group by sex. Rate ratios (RRs) were calculated relative to whites. Multivariable models controlling for insurer, comorbidity, diabetes prevalence, age, and residence location provided final adjusted rates and RRs. Results A total of 1,815 DRPH were seen from 1,515 unique individuals. Unadjusted RRs for DRPH by patient were less than1 in all AA/PI study groups compared with whites, but were highest among Native Hawaiians and Filipinos. In fully adjusted models accounting for higher diabetes prevalence in AA/PI groups, Native Hawaiian (adjusted rate ratio [aRR] = 1.59), Filipino (aRR = 2.26), and Japanese (aRR = 1.86) men retained significantly higher rates of diabetes-related potentially preventable hospitalizations than whites, as did Filipino women (aRR = 1.61). Conclusion Native Hawaiian, Filipino, and Japanese men and Filipino women aged 65 years or older have a higher risk than whites for DRPH. Health care providers and public health programs for elderly patients should consider effective programs to reduce potentially preventable hospitalizations among Native Hawaiian, Filipino, and Japanese men and Filipino women aged 65 years or older.

Rate and Associations of Epididymal Cysts on Pediatric Scrotal Ultrasound

PURPOSE We established the baseline occurrence of epididymal cysts, and the correlation between epididymal cysts and testicular size. MATERIALS AND METHODS We retrospectively reviewed all pediatric scrotal ultrasounds done at our institution in 8 years. We analyzed the proportion of cysts by patient age and compared testicular size in boys with vs without epididymal cysts. RESULTS Of all patients 14.4% had epididymal cysts. The cyst incidence increased with age, ie 35.3% of boys older than 15 years had cysts. Boys with epididymal cysts had larger testes than boys without cysts regardless of side or age (p <0.001). CONCLUSIONS Epididymal cysts are more common in older boys. Boys with epididymal cysts had larger testes than boys without cysts.

Illness Severity and Psychiatric Hospitalization Rates Among Asian Americans and Pacific Islanders

OBJECTIVE The study objective was to fill research gaps about inpatient psychiatric service utilization among Asian Americans and Pacific Islanders (AA/PIs). METHODS Rates of psychiatric hospitalization, illness severity, and length of stay were compared among AA/PI adults overall and across diagnoses (schizophrenia, depression, bipolar, anxiety, and other psychiatric disorders identified by All Patient Refined Diagnosis Related Groups) by using discharge data from all hospitalizations in Hawaii from December 2006 to 2010. Multivariable models adjusted for gender, age, payer, and residence. RESULTS In multivariable analyses of total psychiatric hospitalizations, Chinese (rate ratio [RR]=.22), Japanese (RR=.23), Filipinos (RR=.30), and Native Hawaiians (RR=.37) had significantly lower rates than whites. Native Hawaiians had significantly higher hospitalization rates compared with other AA/PI groups. Length of stay was significantly longer for Chinese (length of stay ratio [LOSR]=1.53), Filipinos (LOSR=1.20), and Japanese (LOSR=1.19) compared with whites, whereas severity of illness was significantly higher for Japanese (odds ratio [OR]=1.36) and Filipinos (OR=1.30). Within specific diagnoses, Native Hawaiians had higher hospitalization rates than other AA/PI groups for depression, bipolar disorder, and anxiety disorder. Chinese, Japanese, and Filipinos had significantly higher illness severity or longer stays than whites for at least one diagnostic category. CONCLUSIONS AA/PI subgroups had lower psychiatric hospitalization rates than whites, but rates varied across AA/PI subgroups. Native Hawaiians had higher hospitalization rates for many diagnoses. Chinese, Japanese, and Filipinos had greater illness severity or longer stays than whites overall and for some diagnoses, whereas Native Hawaiians did not. Disaggregating AA/PI groups provides important insight into mental health services utilization and need.

Abnormal CA-125 levels in menopausal women without ovarian cancer

OBJECTIVE To determine if an abnormal CA-125 level in a menopausal female without ovarian cancer is associated with an increase in mortality. METHODS The Prostate, Lung, Colorectal, and Ovarian Cancer Screening Randomized Controlled (PLCO) Trial is a large multicenter prospective trial conducted by the National Cancer Institute (NCI). Over 78,000 healthy women aged 55-74 were randomized to a screening arm versus a usual medical care arm to evaluate the efficacy of screening in reducing mortality due to ovarian cancer. Women in the screening arm underwent annual screening for ovarian cancer with transvaginal ultrasound and CA-125 levels. There were 38,818 patients without ovarian cancer that had at least one CA-125 level drawn; 1201 (3.09%) had at least one abnormal level. The current study compares mortality in patients that had one or more abnormal CA-125 levels without ovarian cancer versus those with all normal levels. RESULTS Patients with one or more abnormal CA-125 levels, without ovarian cancer, had a significantly higher mortality than patients with all normal CA-125 levels in the PLCO screening trial (p<0.0001). This increased risk extended throughout the follow-up period. Analysis of cause of death listed on the death certificate showed an excess mortality attributable to lung cancer, digestive disease, and endocrine, nutritional, and metabolic disease. CONCLUSION Menopausal females with an elevated CA-125 and without ovarian cancer are exposed to an increased risk of premature mortality.

Ovarian cancer screening in menopausal females with a family history of breast or ovarian cancer

Objective To determine whether annual screening reduces ovarian cancer mortality in women with a family history of breast or ovarian cancer. Methods Data was obtained from the Prostate, Lung, Colorectal, and Ovarian cancer trial, a randomized multi-center trial conducted to determine if screening could reduce mortality in these cancers. The trial enrolled 78,216 women, randomized into either a screening arm with annual serum cancer antigen 125 and pelvic ultrasounds, or usual care arm. This study identified a subgroup that reported a first degree relative with breast or ovarian cancer. Analysis was performed to compare overall mortality and disease specific mortality in the screening versus usual care arm. In patients diagnosed with ovarian cancer, stage distribution, and survival were analyzed as a secondary endpoint. Results There was no significant difference in overall mortality or disease specific mortality between the two arms. Ovarian cancer was diagnosed in 48 patients in the screening arm and 44 patients in the usual care arm. Screened patients were more likely to be diagnosed at an earlier stage than usual care patients. Patients in the screening arm diagnosed with ovarian cancer experienced a significantly improved survival compared to patients in the usual care arm; relative risk 0.66 (95% CI, 0.47 to 0.93). Conclusion Screening did not appear to decrease ovarian cancer mortality in participants with a family history of breast or ovarian cancer. Secondary endpoints, however, showed notable differences. Significantly fewer patients were diagnosed with advanced stage disease in the screening arm; and survival was significantly improved. Further investigation is warranted to assess screening efficacy in women at increased risk.

Risk-Adjusted In-Hospital Mortality Models for Congestive Heart Failure and Acute Myocardial Infarction: Value of Clinical Laboratory Data and Race/Ethnicity.

OBJECTIVE To examine the impact of key laboratory and race/ethnicity data on the prediction of in-hospital mortality for congestive heart failure (CHF) and acute myocardial infarction (AMI). DATA SOURCES Hawaii adult hospitalizations database between 2009 and 2011, linked to laboratory database. STUDY DESIGN Cross-sectional design was employed to develop risk-adjusted in-hospital mortality models among patients with CHF (n = 5,718) and AMI (n = 5,703). DATA COLLECTION/EXTRACTION METHODS Results of 25 selected laboratory tests were requested from hospitals and laboratories across the state and mapped according to Logical Observation Identifiers Names and Codes standards. The laboratory data were linked to administrative data for each discharge of interest from an all-payer database, and a Master Patient Identifier was used to link patient-level encounter data across hospitals statewide. PRINCIPAL FINDINGS Adding a simple three-level summary measure based on the number of abnormal laboratory data observed to hospital administrative claims data significantly improved the model prediction for inpatient mortality compared with a baseline risk model using administrative data that adjusted only for age, gender, and risk of mortality (determined using 3Ms All Patient Refined Diagnosis Related Groups classification). The addition of race/ethnicity also improved the model. CONCLUSIONS The results of this study support the incorporation of a simple summary measure of laboratory data and race/ethnicity information to improve predictions of in-hospital mortality from CHF and AMI. Laboratory data provide objective evidence of a patients condition and therefore are accurate determinants of a patients risk of mortality. Adding race/ethnicity information helps further explain the differences in in-hospital mortality.

Disparities in Potentially Preventable Hospitalizations for Chronic Conditions Among Korean Americans, Hawaii, 2010–2012

Introduction Korean Americans are a growing but understudied population group in the United States. High rates of potentially preventable hospitalizations suggest that primary care is underutilized. We compared preventable hospitalizations for chronic conditions in aggregate and for congestive heart failure (CHF) for Korean Americans and whites in Hawaii. Methods Discharge data from 2010 to 2012 for all hospitalizations of adults in Hawaii for preventable hospitalizations in aggregate and for CHF included 4,345 among Korean Americans and 81,570 among whites. Preventable hospitalization rates for chronic conditions and CHF were calculated for Korean Americans and whites by sex and age group (18–64 y vs ≥65 y). Unadjusted rate ratios for Korean Americans were calculated relative to whites. Multivariate models, controlling for insurance type and comorbidity, provided adjusted rate ratios (aRRs). Results Korean American women and men aged 65 or older were at greater risk of preventable hospitalization overall than white women (aRR, 2.48; P = .003) and white men (aRR, 1.82; P = .049). Korean American men aged 65 or older also were at greater risk of hospitalization for CHF relative to white men (aRR, 1.87; P = .04) and for older Korean American women (aRR, 1.75; P = .07). Younger age groups did not differ significantly. Conclusion Older Korean American patients may have significant disparities in preventable hospitalizations, which suggests poor access to or poor quality of primary health care. Improving primary care for Korean Americans may prevent unnecessary hospitalizations, improve quality of life for Korean Americans with chronic illness, and reduce health care costs.