Biomedical subjects

Honghu Liu

Publications and source records attributed to Honghu Liu.

At least 19 recordsLinked to original sources

PubMed2007

Repeated measures analyses of dose timing of antiretroviral medication and its relationship to HIV virologic outcomes.

Medication adherence is a critical predictor of the effectiveness of antiretroviral medications in the treatment of HIV/AIDS. Studies of adherence, however, have focused primarily on the per cent of prescribed doses taken (per cent adherence). In the Adherence and Efficacy of Protease Inhibitor Therapy study, we collected detailed adherence data including dose timing information as well as data regarding patients' virologic responses. For 48 weeks, adherence data and virologic outcomes were collected every 4 weeks, and demographics and other measures were collected at baseline and at weeks 8, 24, and 48. We constructed eight different dose timing error (DTE) measures and evaluated their associations with virologic outcomes using longitudinal analyses. Repeated measures mixed effect models were fitted to evaluate the predicting power of each of the DTE measures. Among 52 036 electronically measured doses obtained from 122 patients, DTE measures significantly predicted virologic outcomes. Of the eight different DTE measures, the six DTE measures were significantly predictive of virologic outcomes even after controlling for per cent adherence. In conclusion, we identified several measures of DTE that explain HIV virologic outcomes not captured by traditional adherence measures. Investigations of adherence to antiretrovirals would benefit from measuring not only per cent adherence but dose timing adherence.

Adult↗

PubMed2006

A practical method to calibrate self-reported adherence to antiretroviral therapy.

OBJECTIVE: Self-report of antiretroviral medications adherence is inexpensive and simple to use in clinical settings but grossly overestimates adherence. We investigated methods to calibrate patients' self-reported adherence to match objectively measured adherence more closely for the purpose of developing a practical and more accurate self-reported adherence measure. DESIGN: Longitudinal cohort design. METHODS: Using data from 2 prospective longitudinal clinical investigations conducted at 5 HIV clinics, we examined the discrepancy between self-reported adherence and objectively measured adherence. We evaluated the relation between attitudinal measures and the degree of discrepancy and used a cross-validation approach to propose candidate items to improve adherence survey methodology. RESULTS: Among 330 patients, self-reported adherence was consistently higher than objectively measured adherence. The best calibration models included the patient's self-reported adherence, duration of the antiretroviral regimen, and attitudinal measures (ability to take medication as instructed, believing medication can help one to live longer, whether or not it is too troublesome to take antiretrovirals, and feeling things are going the right way). CONCLUSION: The method efficiently identified survey items to improve self-reported adherence measurement. The calibrated measure more closely approximates objectively measured adherence and is more sensitive for detecting nonadherence. These models merit evaluation in other settings.

Adult↗

PubMed2006

Substance abuse and medication adherence among HIV-positive women with histories of child sexual abuse.

Substance abuse increases the risks for infections and impairs medication adherence among HIV/AIDS patients. However, little is known about the characteristics of substance abuse and its impact on medication adherence among HIV-positive women with a history of child sexual abuse (CSA). In the present study, 148 HIV-positive women with a history of CSA completed a structured interview assessing CSA severity, psychological status, substance abuse, medication adherence, and sexual decision-making. Severity of CSA was significantly associated with substance use but not with adherence. Participants who had used hard drugs and who had lower self-esteem and adherence self-efficacy reported significantly lower levels of adherence. Additional research on how CSA experiences impact health behaviors is needed to help develop culturally congruent interventions to reduce risk behaviors and facilitate better medication adherence for this vulnerable population.

Adult↗

PubMed2006

Severity of child sexual abuse, post- traumatic stress and risky sexual behaviors among HIV-positive women.

Child sexual abuse (CSA) has been shown to enhance risk for HIV infection and other adverse outcomes. However, most studies examine the effects of a single incident of CSA rather than the full burden of abuse over the life span in predicting these adverse outcomes. A multi-dimensional approach was used in this study to examine the severity of abuse as a predictor of post-traumatic stress, depression, sexual symptoms, and risky sexual behaviors in a multi-ethnic sample of 147 HIV-positive women. Multivariate models indicated that experiencing both intrafamilial and extrafamilial CSA, adult sexual abuse (ASA) and Latina ethnicity predicted PTSD symptoms. ASA also predicted sexual trauma symptoms. Also, CSA and adult re-victimization contributed independently to risk for PTSD and sexual trauma symptoms, but not for risky sexual behaviors. The results support the need for interventions for HIV-positive women that address the full burden of abuse experienced and its sequelae.

Adult↗

PubMed2006

A pilot study of health beliefs and attitudes concerning measures of antiretroviral adherence among prisoners receiving directly observed antiretroviral therapy.

High level adherence to antiretroviral therapy (ART) is required to achieve and maintain suppression of HIV replication. Although directly observed therapy (DOT) has been suggested as an intervention to improve adherence, there is a paucity of data describing the attitudes and beliefs regarding DOT for ART among HIV-infected individuals. This study was designed to evaluate the acceptability and psychometric properties of a survey instrument for use in assessing barriers and facilitators of adherence to ART DOT in prison. From July 1, 1999 to April 1, 2000, we piloted an interviewer-administered questionnaire to assess health beliefs and attitudes regarding HIV treatment among 65 HIV-infected prison inmates receiving one or more of their antiretrovirals via directly observed therapy (DOT). The first 24 participants were administered the questionnaire to determine the feasibility of surveying prisoners in a correctional setting. There were no adherence data collected on these participants. The remaining 41 participants had their adherence measured in addition to receiving the questionnaire. Thirty-one were included in the final analysis because 10 did not complete the study. Multiple antiretroviral adherence measures (electronic device medication monitoring [eDEM] caps, medication administration records [MARs], and pill counts) were assessed among a subset of the participants (n = 31) and correlated to the instrument response items. The median internal consistency reliability coefficient for the multi-item scales was 0.79. The strongest correlation between inmates' beliefs and their adherence was between "positive beliefs about protease inhibitors" and the MAR adherence measure (r = 0.72; p < 0.001). This study provides preliminary support for the psychometric properties of the survey in this correctional setting.

Anti-Retroviral Agents↗

PubMed2006

A comprehensive evaluation of survey questions for adherence to antiretroviral medications and exploratory analyses for identifying optimal sets of survey questions.

Although many methods for assessing adherence have been developed, most are not feasible for busy clinical settings. Using patients from the Adherence and Efficacy of Protease inhibitor Therapy (ADEPT) study (1998-2000), we systematically evaluated the relationship between psychosocial, environmental, clinical, and other factors with adherence to create composite variables (CVs) that are efficient with high sensitivity for detecting nonadherence and great potential for busy clinics. Eligible patients were protease inhibitor naïve or started a regimen within 3 months from baseline. Of the 128 patients who responded to survey at baseline, weeks 8, 24, and/or 48, mean (standard deviation [SD]) age was 39.3 (8.2) years with 81% male. About half of the patients were Latino, followed by 28% African American and 14% Caucasian. Sixteen percent reported injection drug use, and 40% had male-male sex. Mean CD4 count was 184.8 cells/mm(3) with a range from 1 to 1130 cells/mm(3). Thirty-two variables had a significant association with adherence at one or two time points and 9 were significantly associated with adherence over time. Among these significant factors, 8 also had a relationship with a clearly monotonic trend, by which 219 CVs were formed. Among these CVs, 8 were significantly associated with adherence and had a relationship with monotonic trend. Compared to traditional self-reported adherence, CVs had much higher sensitivities (p < 0.001) for detecting nonadherence. We conclude that CVs consisting of a combination of psychological, behavior, and adherence questions may be reasonable substitutes for direct adherence questions, which are limited by problems with recall and social biases. Trust in physicians, having a child, history of substance use, CD4 count, and belief that antiretrovirals can help living longer or improve quality of life can efficiently predict nonadherence. Because these variables are readily obtainable in clinical settings, these selected questions may provide a clinically useful means of screening patients for antiretroviral medication nonadherence.

Adult↗

PubMed2006

What is the concordance between the medical record and patient self-report as data sources for ambulatory care?

BACKGROUND: The validity of quality of care assessments relies upon data quality, yet little is known about the relative completeness and validity of data sources for evaluating the quality of care. OBJECTIVES: We evaluated concordance between ambulatory medical record and patient survey data. Levels of concordance, variations by type of item, sources of disagreement between data sources, and implications for quality of care assessment efforts are discussed. DESIGN AND SUBJECTS: This was an observational study that included 1270 patients sampled from 39 West Coast medical organizations with at least 1 of the following: diabetes, ischemic heart disease, asthma or chronic obstructive pulmonary disease, or low back pain. MEASURES: Items from both data sources were grouped into 4 conceptual domains: diagnosis, clinical services delivered, counseling and referral, and medication use. We present total agreement, kappa, sensitivity, and specificity at the item and domain-levels and for all items combined. RESULTS: We found good concordance between survey and medical records overall, but there was substantial variation within and across domains. The worst concordance was in the counseling and referrals domain, the best in the medication use domain. Patients were able to report with good sensitivity on memorable items. CONCLUSIONS: Quality ratings are likely to vary in differing directions, depending on the data source used. The most appropriate data source for analyses of components of and overall quality of care must be considered in light of study objectives and resources. We recommend data collection from multiple sources to most accurately portray the patient and provider experience of medical care.

Adolescent↗

PubMed2006

Repeated measures longitudinal analyses of HIV virologic response as a function of percent adherence, dose timing, genotypic sensitivity, and other factors.

BACKGROUND: Adherence to antiretroviral medications is critical to achieving HIV viral suppression. Studies have been limited to cross-sectional analyses using measures that reflect only the percentage of prescribed doses taken (percent adherence), however. The contribution of dose timing and other factors to achieving virologic suppression has received less scrutiny. METHODS: In a longitudinal study, we collected detailed adherence information using multiple tools along with demographic, clinical, social-behavioral, and virologic measures. Subjects were followed for 48 weeks. Percent adherence, dose-timing, genotypic sensitivity, and virologic outcomes were collected every 4 weeks. Repeated measures mixed effects models (RMMEMs) were used to model the relation between virologic outcomes and adherence as well as genotypic sensitivity and others. RESULTS: Of the 141 subjects, mean percent adherence was 73% with a downward trend. Viral load (VL) dropped significantly (P = 0.01) over time. RMMEMs revealed that higher genotypic sensitivity, higher percent adherence, lower baseline VL, longer inclusion in the study, earlier HIV stage, and smaller dose-timing error were significantly associated with lower VL. In multivariate modeling, a 0.50 increase in the genotypic sensitivity score, a 10% increase in adherence, and a decrease of 3 hours of dose-timing error were associated with a decrease in log10 HIV RNA at 48 weeks of 0.69, 0.54, and 0.48, respectively (P < 0.05 for each). CONCLUSIONS: Long-term viral suppression requires consistent and high percent adherence accompanied by optimal interdose intervals. Efforts to improve viral outcomes should address not only missed doses but excessive variation in dose timing and prevention of adherence decline over time. Preventing the development and transmission of resistant variants is also critically important.

Adult↗

PubMed2005

Approaches and recommendations for estimating minimally important differences for health-related quality of life measures.

We describe currently available approaches for estimating the minimally important difference (MID) and their associated strengths and weaknesses. Specifically, we show that anchor-based methods should be the primary method of estimating the MID because of the limitations of distribution-based methods. In addition, we provide recommendations for estimating the MID in future research.

Data Interpretation, Statistical↗

PubMed2005

Imputation of SF-12 health scores for respondents with partially missing data.

OBJECTIVE: To create an efficient imputation algorithm for imputing the SF-12 physical component summary (PCS) and mental component summary (MCS) scores when patients have one to eleven SF-12 items missing. STUDY SETTING: Primary data collection was performed between 1996 and 1998. STUDY DESIGN: Multi-pattern regression was conducted to impute the scores using only available SF-12 items (simple model), and then supplemented by demographics, smoking status and comorbidity (enhanced model) to increase the accuracy. A cut point of missing SF-12 items was determined for using the simple or the enhanced model. The algorithm was validated through simulation. DATA COLLECTION: Thirty-thousand-three-hundred and eight patients from 63 physician groups were surveyed for a quality of care study in 1996, which collected the SF-12 and other information. The patients were classified as "chronic" patients if they reported that they had diabetes, heart disease, asthma/chronic obstructive pulmonary disease, or low back pain. A follow-up survey was conducted in 1998. PRINCIPAL FINDINGS: Thirty-one percent of the patients missed at least one SF-12 item. Means of variance of prediction and standard errors of the mean imputed scores increased with the number of missing SF-12 items. Correlations between the observed and the imputed scores derived from the enhanced models were consistently higher than those derived from the simple model and the increments were significant for patients with > or =6 missing SF-12 items (p<.03). CONCLUSION: Missing SF-12 items are prevalent and lead to reduced analytical power. Regression-based multi-pattern imputation using the available SF-12 items is efficient and can produce good estimates of the scores. The enhancement from the additional patient information can significantly improve the accuracy of the imputed scores for patients with > or =6 items missing, leading to estimated scores that are as accurate as that of patients with <6 missing items.

Adult↗

PubMed2005

Oral white patches in a national sample of medical HIV patients in the era of HAART.

OBJECTIVES: Several types of HIV-related oral mucosal conditions have been reported to occur during the course of HIV disease progression. Of these, few may be manifested as 'white' lesions and many are noticeable to the patient. This paper examines the relationships between social, behavioral and medical aspects of HIV infection and reporting an occurrence of oral white patches (OWP) by HIV-infected patients. METHODS: The subjects are participants in all three interviews in the HIV Cost and Services Utilization Study (HCSUS). The subjects were selected using a three-stage probability sampling design. The multivariate analysis is based on 2109 subjects with nonmissing binary outcome variable for all three waves representing a national sample of 214 000 individuals. The multivariate model was fitted using generalized estimating equations (GEE) by implementing the XTGEE command in STATA. RESULTS: We estimate that 75 000 persons (35%) reported at least one incident of OWP, of these 14 000 reported having OWP during all three interviews, and that the rate of reporting declined over the three HCSUS waves. The multivariate analysis showed seven variables that were significant predictors of at least one report of OWP. CONCLUSIONS: Compared with persons on HAART therapy, patients on other regimens or taking no antiviral medications were 23-46% more likely to report an incident of OWP. Compared with whites, African Americans were 32% less likely to report OWP, while current smokers were 62% more likely than nonsmokers. Being diagnosed with AIDS and having CD4 counts less than 500 significantly increased the likelihood of reporting OWP.

Adolescent↗

PubMed2005

A longitudinal analysis of unmet need for oral treatment in a national sample of medical HIV patients.

This longitudinal study examines perceived unmet dental need in a nationally representative probability sample of HIV-infected persons in medical care. A logistic regression analysis modeled the relationship between unmet need and explanatory variables. We estimate that 40% of HIV/AIDS patients report an unmet need associated with being male, being unemployed, injecting drugs, being heterosexual, lacking dental insurance, and having less education. Disparities in unmet need are related to socioeconomic status rather than to disease stage or ethnicity.

Adult↗

PubMed2004

No evidence of an association between transient HIV viremia ("Blips") and lower adherence to the antiretroviral medication regimen.

BACKGROUND: Transient human immunodeficiency virus (HIV) viremia, a common phenomenon among patients taking antiretroviral therapy, is often attributed to lapses in adherence to the medication regimen. We investigated this relationship in a prospective observational cohort of 128 patients initiating a new regimen. METHODS: A case of transient viremia was defined as an HIV RNA level of 40-1000 copies/mL ("blip") sandwiched between 2 months of HIV RNA levels <40 copies/mL ("pre" and "post"). Adherence was most often measured with a composite adherence score (CAS), which is primarily based on electronically measured adherence. Case subjects' adherence and dose-timing was compared with (1) that of other patients (control subjects), who had undetectable virus loads for 3 consecutive months, and (2) that during periods of sustained undetectable virus loads among the case subjects themselves, if available. RESULTS: Among the 28 case subjects, mean CAS-measured adherence did not decrease before transient viremia; adherence during the pre, blip, and post periods were 86%, 84%, and 80%, respectively. Control subjects had lower adherence levels during the corresponding 3 months (77%, 79%, and 75%, respectively; P = .046). Among the 19 patients able to serve as their own controls, CAS-measured adherence was higher during the period of transient viremia than during control periods (P = .01). Similar relationships were found when comparing only electronically measured adherence on a week-wise basis. There were no significant differences in dose-timing error between case subjects and control subjects. CONCLUSIONS: We found no evidence that transient HIV viremia is associated with decreases in adherence or differences in dose-timing. Other etiologies for transient viremia should be evaluated.

Adult↗

PubMed2004

Interleukin 6 and interleukin 8 as potential biomarkers for oral cavity and oropharyngeal squamous cell carcinoma.

BACKGROUND: Since morbidity and mortality rates due to oral cavity and oropharyngeal squamous cell carcinoma (OSCC) have improved little in the past 30 years, early detection or prevention of this disease is likely to be most effective. Using laser-capture microdissection, we have identified the expression of 2 cellular genes that are uniquely associated with OSCC: interleukin (IL) 6 and IL-8. These cytokines may contribute to the pathogenesis of this disease, and have been linked with increased tumor growth and metastasis. OBJECTIVES: To investigate whether IL-6 and/or IL-8 could serve as informative biomarkers for OSCC in saliva and/or serum and to determine if there is a role for saliva as a diagnostic medium for OSCC. PATIENTS AND METHODS: Patients with newly diagnosed T1 or T2 oral cavity or oropharyngeal histologically confirmed squamous cell carcinoma were recruited for the study. Age and sex-matched disease-free subjects were used as controls. Using quantitative real-time polymerase chain reaction analysis and enzyme-linked immunosorbent assay, we respectively assessed the expression of IL-6 and IL-8 in serum (controls, n = 32; patients with OSCC, n = 19) and saliva (controls, n = 32; patients with OSCC, n = 32) at the messenger RNA (mRNA) and protein levels. MAIN OUTCOME MEASURES: Specificity and sensitivity of these biomarkers for OSCC and their predictive value. RESULTS: Interleukin 8 was detected at higher concentrations in saliva (P<.01) and IL-6 was detected at higher concentrations in serum of patients with OSCC (P<.01). We confirmed these results at both the mRNA and the protein levels, and the results were concordant. The concentration of IL-8 in saliva and IL-6 in serum did not appear to be associated with sex, age, or alcohol or tobacco use (P>.75). Using statistical analysis, we were able to determine the threshold value, sensitivity, and specificity of each biomarker, as well as a combination of biomarkers, for detecting OSCC. CONCLUSIONS: Our findings indicate that IL-8 in saliva and IL-6 in serum hold promise as biomarkers for OSCC. A saliva-based test could be a cost-effective adjunctive tool in the diagnosis and follow-up of patients with OSCC.

Adult↗

PubMed2004

The efficacy of an integrated risk reduction intervention for HIV-positive women with child sexual abuse histories.

Child sexual abuse (CSA) is associated with HIV risk behaviors [Bensley, L., Van Eenwyk, J., and Simmons, K. W., 2003.] and more prevalent among women living with HIV than in the general population [Koenig, L. J., and Clark, H., 2004]. This randomized Phase~I clinical trial tested the impact of a culturally congruent psychoeducational intervention designed to reduce sexual risks and increase HIV medication adherence for HIV-positive women with CSA histories. An ethnically diverse sample of 147 women were randomized to two conditions: an 11-session Enhanced Sexual Health Intervention (ESHI) or an attention control. Results based on "intent to treat'' analyses of pre-post changes are reported here. Additional analyses explored whether the observed effects might depend on "intervention dose,'' i.e., number of sessions attended. Women in the ESHI condition reported greater sexual risk reduction than women in the control condition. Although there were no differences between women in the ESHI and control groups on medication adherence, women in the ESHI condition who attended 8 or more sessions reported greater medication adherence at posttest than control women. The findings provide initial support for this culturally and gender-congruent psychoeducational intervention for HIV-positive women with CSA, and highlight the importance of addressing the effects of CSA on sexual risk reduction and medication adherence in preventive interventions for women.

Adult↗

PubMed2004

Case finding for population-based studies of rheumatoid arthritis: comparison of patient self-reported ACR criteria-based algorithms to physician-implicit review for diagnosis of rheumatoid arthritis.

OBJECTIVE: To evaluate the interrater reliability of rheumatologist diagnosis of rheumatoid arthritis (RA) and the concordance between rheumatologist and computer algorithms for assessing the accuracy of a diagnosis of RA. METHODS: Self-reported data regarding symptoms and signs for a diagnosis of RA were considered by a panel of rheumatologists and by computer algorithms to assess the probability of a diagnosis of RA for 90 patients. The rheumatologists' review was validated through medical record. RESULTS: The interrater reliability among rheumatologists regarding a diagnosis of RA was 84%; the chance-corrected agreement (kappa) was 0.66. Agreement between the rheumatologists' rating and the best-performing algorithm was 95%. Using rheumatologist's review as a standard, the sensitivity of the algorithm was 100%, specificity was 88%, and the positive predictive value was 91%. The validation of rheumatologist's review by medical record showed 81% sensitivity, 60% specificity, and 78% positive predictive value. CONCLUSION: Reliability of rheumatologists' assignment of a diagnosis of RA by using self-report data is good. Algorithms defining symptoms as either joint swelling or tenderness with symptom duration >or=4 weeks have a better agreement with rheumatologist's diagnosis than do ones relying on a longer symptom duration. RELEVANCE: These findings have important implications for health services research and quality improvement interventions pertinent to case finding for RA through self-report data.

Algorithms↗

PubMed2004

Development and evaluation of a patient self-report case-finding method for rheumatoid arthritis.

OBJECTIVE: To describe the development and evaluation of a patient self-report case-finding method for rheumatoid arthritis (RA) not dependent on direct contact with the treating physicians. METHODS: The American College of Rheumatology criteria for RA diagnosis were adapted for patient self-report using a questionnaire, and alternative scoring algorithms were evaluated to balance case-finding sensitivity and specificity. Positive rheumatoid factor tests were used to identify 1053 individuals in 2 large healthcare organizations; 440 agreed to receive study materials. Case-finding results were validated by medical record review (MRR) for a random sample of 90 patients. Three scoring algorithms were compared with MRR for likelihood of RA diagnosis. Cases not classifiable by algorithm were flagged and reviewed by 2 expert physicians for likelihood of RA diagnosis. RESULTS: Pilot testing demonstrated that patients comprehended the questionnaire and were willing to answer the questions. Completed questionnaires were returned by 265 (60%) of the 440 patients contacted. Following expert physician review of 16 flagged cases in the 90-patient MRR subsample, the most accurate scoring algorithm demonstrated 80% sensitivity, 67% specificity, 74% accuracy, and 77% positive predictive value for detecting early RA. CONCLUSION: The case-finding method represents a promising tool for identifying RA patients, with potential application in research and quality-assurance activities. RELEVANCE: This case-finding method should be useful in research and quality-assurance efforts requiring identification of RA patients treated by all types of providers in healthcare organizations in which centralized laboratory data are available.

Arthritis, Rheumatoid↗

PubMed2004

Linking hospital discharge and death records--accuracy and sources of bias.

BACKGROUND AND OBJECTIVE: The aim of this study was to develop and apply an automated linkage algorithm to 10 years of California hospitalization discharge abstracts and death records (1990 to 1999), evaluate linkage accuracy, and identify sources of bias. METHODS: Among the 1,858,458 acute hospital discharge records with unique social security numbers (SSNs) from 1 representative year of discharge data (1997), which had at least 2 years of follow-up, 66,410 of 69,757 deaths occurring in the hospital (95%) and 66,998 of 1,788,701 of individuals discharged alive (3.7%) linked to death records. Linkage sensitivity and specificity were estimated as 0.9524 and 0.9998 and positive and negative predictive values as 0.994 and 0.998 (corresponding to 400 incorrect death linkages among out-of-hospital death record linkages and 3,300 unidentified record pairs among unlinked live discharges). RESULTS: Based upon gold standard linkage rates, discharge records for those of age 1 year and older without SSNs may have 2,520 additional uncounted posthospitalization deaths at 1 year after admission. Gold standard comparison for those with SSNs showed women, the elderly, and Hispanics and non-Hispanic Blacks had more unlinked hospital death records, although absolute differences were small. The concentration of unidentified linkages among discharge records of traditionally vulnerable populations may result in understating mortality rates and other estimates (i.e., events with competing hazard of death) for these populations if SSN is differentially related to a patient's disease severity and comorbidities. CONCLUSION: Because identification of cases of out-of-hospital deaths has improved over the past decade, observed improvements in patient survival over this time are likely to be conservative.

Adolescent↗