Xueya Cai

Clinical characteristics and outcomes of Medicare patients undergoing total hip arthroplasty, 1991-2008.

CONTEXT Total hip arthroplasty is a common surgical procedure but little is known about longitudinal trends. OBJECTIVE To examine demographics and outcomes of patients undergoing primary and revision total hip arthroplasty. DESIGN, SETTING, AND PARTICIPANTS Observational cohort of 1,453,493 Medicare Part A beneficiaries who underwent primary total hip arthroplasty and 348,596 who underwent revision total hip arthroplasty. Participants were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes for primary and revision total hip arthroplasty between 1991 and 2008. MAIN OUTCOME MEASURES Changes in patient demographics and comorbidity, hospital length of stay (LOS), mortality, discharge disposition, and all-cause readmission rates. RESULTS Between 1991 and 2008, the mean age for patients undergoing primary total hip arthroplasty increased from 74.1 to 75.1 years and for revision total hip arthroplasty from 75.8 to 77.3 years (P < .001). The mean number of comorbid illnesses per patient increased from 1.0 to 2.0 for primary total hip arthroplasty and 1.1 to 2.3 for revision (P < .001). For primary total hip arthroplasty, mean hospital LOS decreased from 9.1 days in 1991-1992 to 3.7 days in 2007-2008 (P = .002); unadjusted in-hospital and 30-day mortality decreased from 0.5% to 0.2% and from 0.7% to 0.4%, respectively (P < .001). The proportion of primary total hip arthroplasty patients discharged home declined from 68.0% to 48.2%; the proportion discharged to skilled care increased from 17.8% to 34.3%; and 30-day all-cause readmission increased from 5.9% to 8.5% (P < .001). For revision total hip arthroplasty, similar trends were observed in hospital LOS, in-hospital mortality, discharge disposition, and hospital readmission rates. CONCLUSION Among Medicare beneficiaries who underwent primary and revision hip arthroplasty between 1991 and 2008, there was a decrease in hospital LOS but an increase in the rates of discharge to postacute care and readmission.

Haemophilus haemolyticus: a human respiratory tract commensal to be distinguished from Haemophilus influenzae.

BACKGROUND Haemophilus influenzae is a common pathogen in adults with chronic obstructive pulmonary disease (COPD). In a prospective study, selected isolates of apparent H. influenzae had an altered phenotype. We tested the hypothesis that these variant strains were genetically different from typical H. influenzae. METHODS A prospective study of adults with COPD was conducted. Strains of apparent H. influenzae obtained from a range of clinical sources were evaluated by ribosomal DNA sequence analysis, multilocus sequence analysis, DNA-DNA hybridization, and sequencing of the conserved P6 gene. RESULTS Variant strains were determined to be Haemophilus haemolyticus by means of 4 independent methods. Analysis of 490 apparent H. influenzae strains, identified by standard methods, revealed that 39.5% of sputum isolates and 27.3% of nasopharyngeal isolates were H. haemolyticus. Isolates obtained from normally sterile sites were all H. influenzae. In a prospective study, acquisitions of new strains of H. haemolyticus were not associated with exacerbations of COPD, whereas 45% of acquisitions of new strains of H. influenzae were associated with exacerbations. CONCLUSIONS Standard methods do not reliably distinguish H. haemolyticus from H. influenzae. H. haemolyticus is a respiratory tract commensal. The recognition that some strains of apparent H. influenzae are H. haemolyticus substantially strengthens the association of true H. influenzae with clinical infection.

Pseudomonas aeruginosa in chronic obstructive pulmonary disease.

RATIONALE Pseudomonas aeruginosa is isolated from adults with chronic obstructive pulmonary disease (COPD) in cross-sectional studies. However, patterns of carriage and the role of P. aeruginosa in COPD are unknown. OBJECTIVES To elucidate carriage patterns, phenotypes of strains, clinical manifestations, and the antibody response to P. aeruginosa in COPD. METHODS A prospective study of adults with COPD was conducted. Isolates of P. aeruginosa were subjected to genotypic and phenotypic analysis. Sputum samples were studied for P. aeruginosa DNA, and immune responses were assayed. MEASUREMENTS AND MAIN RESULTS We analyzed longitudinal clinical data, sputum cultures, pulsed-field gel electrophoresis of bacterial DNA, polymerase chain reaction of sputum, and immunoblot assays of serum. Fifty-seven episodes of acquisition of strains of P. aeruginosa were observed in 39 of 126 patients over 10 years. Acquisition of a new strain was associated with exacerbation. Thirty-one episodes of carriage were followed by clearance of the strain; 16 were of short (<1 mo) duration. Thirteen strains demonstrated persistence, and 13 strains were of indeterminate duration. Six strains were mucoid and were more likely to persist than nonmucoid strains (P = 0.005). Antibody responses developed in 53.8% of persistent carriage and in only 9.7% of short-term carriage episodes (P = 0.003). Antibiotics did not account for clearance. CONCLUSIONS Two distinct patterns of carriage by P. aeruginosa were observed: (1) short-term colonization followed by clearance and (2) long-term persistence. Mucoid strains showed persistence. Acquisition of P. aeruginosa is associated with the occurrence of an exacerbation. Serum antibody responses do not mediate clearance of P. aeruginosa.

A high-risk study of bipolar disorder. Childhood clinical phenotypes as precursors of major mood disorders.

CONTEXT The childhood precursors of adult bipolar disorder (BP) are still a matter of controversy. OBJECTIVE To report the lifetime prevalence and early clinical predictors of psychiatric disorders in offspring from families of probands with DSM-IV BP compared with offspring of control subjects. DESIGN A longitudinal, prospective study of individuals at risk for BP and related disorders. We report initial (cross-sectional and retrospective) diagnostic and clinical characteristics following best-estimate procedures. SETTING Assessment was performed at 4 university medical centers in the United States between June 1, 2006, and September 30, 2009. PARTICIPANTS Offspring aged 12 to 21 years in families with a proband with BP (n = 141, designated as cases) and similarly aged offspring of control parents (n = 91). MAIN OUTCOME MEASURE Lifetime DSM-IV diagnosis of a major affective disorder (BP type I; schizoaffective disorder, bipolar type; BP type II; or major depression). RESULTS At a mean age of 17 years, cases showed a 23.4% lifetime prevalence of major affective disorders compared with 4.4% in controls (P = .002, adjusting for age, sex, ethnicity, and correlation between siblings). The prevalence of BP in cases was 8.5% vs 0% in controls (adjusted P = .007). No significant difference was seen in the prevalence of other affective, anxiety, disruptive behavior, or substance use disorders. Among case subjects manifesting major affective disorders (n = 33), there was an increased risk of anxiety and externalizing disorders compared with cases without mood disorder. In cases but not controls, a childhood diagnosis of an anxiety disorder (relative risk = 2.6; 95% CI, 1.1-6.3; P = .04) or an externalizing disorder (3.6; 1.4-9.0; P = .007) was predictive of later onset of major affective disorders. CONCLUSIONS Childhood anxiety and externalizing diagnoses predict major affective illness in adolescent offspring in families with probands with BP.

Long-term anticholinergic use and the aging brain

Older Americans are facing an epidemic of chronic diseases and are thus exposed to anticholinergics (ACs) that might negatively affect their risk of developing mild cognitive impairment (MCI) or dementia.

Mental Illness and Hospitalization for Ambulatory Care Sensitive Medical Conditions

Background:Hospitalization due to ambulatory care sensitive (ACS) medical conditions is widely used as an indicator of poor primary care access and effectiveness. It is unknown whether patients with mental disorders have higher ACS admission rate, compared with patients without mental disorders. Objective:To compare the ACS admission pattern and its resultant hospital cost and length of stay (LOS) between medical patients with and without coexisting mental disorders. Methods:Using New York State hospital discharge data for 2004, we conducted a retrospective cohort study on inpatient cases who were aged 20–64 years and hospitalized due to either ACS condition or non-ACS “marker” condition. Multivariate regression was used to estimate the relative odds of ACS admissions and the incremental resource use for mentally ill patients during ACS hospitalization. Results:Inpatient cases with mental disorders (N = 38,514) were more likely than others (N = 116,798) to have ACS admission [adjusted odds ratio (AOR), 2.30; 95% confidence interval (CI), 2.17–2.43] relative to admission due to marker conditions. During ACS hospitalization, mentally ill cases showed an average incremental cost of

Association of Race and Sites of Care With Pressure Ulcers in High-Risk Nursing Home Residents

556 (95% CI,

Characterization of igaB, a Second Immunoglobulin A1 Protease Gene in Nontypeable Haemophilus influenzae

340–

Epitope mapping immunodominant regions of the PilA protein of nontypeable Haemophilus influenzae (NTHI) to facilitate the design of two novel chimeric vaccine candidates.

778), and an average incremental LOS of 0.7 days (95% CI, 0.6–0.8 days). The higher ACS admission rate and hospital resource consumption were most pronounced for those with major depression, other psychoses, and combined psychiatric and substance-abuse disorders. Conclusions:Patients with mental disorders experience higher risk of hospitalization due to ACS medical conditions than the general population. During an ACS hospitalization, patients with mental disorders have longer length of stay and higher hospital cost than other patients.

Differential Genome Contents of Nontypeable Haemophilus influenzae Strains from Adults with Chronic Obstructive Pulmonary Disease

CONTEXT A variety of nursing home quality improvement programs have been implemented during the last decade but their implications for racial disparities on quality are unknown. OBJECTIVES To determine the longitudinal trend of racial disparities in pressure ulcer prevalence among high-risk, long-term nursing home residents and to assess whether persistent disparities are related to where residents received care. DESIGN, SETTING, AND PARTICIPANTS Observational cohort study of pressure ulcer rates in 2.1 million white and 346,808 black residents of 12,473 certified nursing homes in the United States that used the nursing home resident assessment; Online Survey, Certification, and Reporting files; and Area Resource Files for 2003 through 2008. Nursing homes were categorized according to their proportions of black residents. MAIN OUTCOME MEASURES Risk-adjusted racial disparities between and within sites of care and risk-adjusted odds of pressure ulcers in stages 2 through 4 for black and white residents receiving care in different nursing home facilities. RESULTS Pressure ulcer rates decreased overall from 2003 through 2008 but black residents of nursing homes showed persistently higher pressure ulcer rates than white residents. In 2003, the pressure ulcer rate was 16.8% (95% confidence interval [CI], 16.6%-17.0%) for black nursing home residents compared with 11.4% (95% CI, 11.3%-11.5%) for white residents; in 2008, the rate was 14.6% (95% CI, 14.4%-14.8%) compared with 9.6% (95% CI, 9.5%-9.7%), respectively (P >.05 for trend of disparities). In nursing homes with the highest percentages of black residents (≥35%), both black residents (unadjusted rate of 15.5% [95% CI, 15.2%-15.8%] in 2008; adjusted odds ratio [AOR], 1.59 [95% CI, 1.52-1.67]) and white residents (unadjusted rate of 12.1% [95% CI, 11.8%-12.4%]; AOR, 1.33 [95% CI, 1.26-1.40]) had higher rates of pressure ulcers than nursing homes serving primarily white residents (concentration of black residents <5%), in which white residents had an unadjusted rate of 8.8% (95% CI, 8.7%-8.9%). CONCLUSIONS From 2003 through 2008, the prevalence of pressure ulcers among high-risk nursing home residents was higher among black residents than among white residents. This disparity was in part related to the site of nursing home care.