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Biomedical subjects

Joseph C Gardiner

Publications and source records attributed to Joseph C Gardiner.

17 recordsLinked to original sources

A dynamic model for estimating changes in health status and costs.

We develop an innovative method to assess total treatment costs over a finite period of time while incorporating the dynamics of change in the health status of patients. Costs are incurred through medical care use while patients sojourn in health states. Because complete ascertainment of costs and observation of events are not always feasible, some patient utilization will be incomplete and events will also be censored. A Markov model is used to estimate the transition probabilities between health states and the impact of patient variables on transition intensities. A mixed-effects model is used for sojourn costs with transition times as random effects and patient variables as fixed effects. The models are combined to estimate net present values (NPVs) of expenditures over a finite time interval as a function of patient characteristics. The method is applied to a data set of 624 incident cases of cancer. Physical functioning after cancer diagnosis was assessed periodically through structured interviews. The outcomes of interest are normal physical function, impaired physical function, or the terminal state, dead. Charges were obtained from Medicare claim files for 2 years following cancer diagnosis. For demonstration purposes, we estimate NPVs for charges incurred over 2 years by cancer site and cancer stage. Our method, a joint regression model, provides a flexible approach to assessing the influence of patient characteristics on both cost and health outcomes while accommodating heteroscedasticity, skewness and censoring in the data.

Female↗

Changes in practice patterns affecting in-hospital and post-discharge survival among ACS patients.

BACKGROUND: Adherence to clinical practice guidelines for the treatment of specific illnesses may result in unexpected outcomes, given that multiple therapies must often be given to patients with diverse medical conditions. Yet, few studies have presented empirical evidence that quality improvement (QI) programs both change practice by improving adherence to guidelines and improve patient outcomes under the conditions of actual practice. Thus, we focus on patient survival, following hospitalization for acute coronary syndrome in three successive patient cohorts from the same community hospitals, with a quality improvement intervention occurring between cohorts two and three. METHODS: This study is a comparison of three historical cohorts of Acute Coronary Syndrome (ACS) patients in the same five community hospitals in 1994-5, 1997, 2002-3. A quality improvement project, the Guidelines Applied to Practice (GAP), was implemented in these hospitals in 2001. Study participants were recruited from community hospitals located in two Michigan communities during three separate time periods. The cohorts comprise (1) patients enrolled between December 1993 and April 1995 (N = 814), (2) patients enrolled between February 1997 and September 1997 (N = 452), and (3) patients enrolled between January 14, 2002 and April 13, 2003 (N = 710). Mortality data were obtained from Michigan's Bureau of Vital Statistics for all three patient cohorts. Predictor variables, obtained from medical record reviews, included demographic information, indicators of disease severity (ejection fraction), co-morbid conditions, hospital treatment information concerning most invasive procedures and the use of ace-inhibitors, beta-blockers and aspirin in the hospital and as discharge recommendations. RESULTS: Adjusted in-hospital mortality showed a marked improvement with a HR = 0.16 (p < 0.001) comparing 2003 patients in the same hospitals to those 10 years earlier. Large gains in the in-hospital mortality were maintained based on 1-year mortality rates after hospital discharge. CONCLUSION: Changes in practice patterns that follow recommended guidelines can significantly improve care for ACS patients. In-hospital mortality gains were maintained in the year following discharge.

Hospitalization↗

Longitudinal analysis of censored medical cost data.

This paper applies the inverse probability weighted (IPW) least-squares method to estimate the effects of treatment on total medical cost, subject to censoring, in a panel-data setting. IPW pooled ordinary-least squares (POLS) and IPW random effects (RE) models are used. Because total medical cost might not be independent of survival time under administrative censoring, unweighted POLS and RE cannot be used with censored data, to assess the effects of certain explanatory variables. Even under the violation of this independency, IPW estimation gives consistent asymptotic normal coefficients with easily computable standard errors. A traditional and robust form of the Hausman test can be used to compare weighted and unweighted least squares estimators. The methods are applied to a sample of 201 Medicare beneficiaries diagnosed with lung cancer between 1994 and 1997.

Aged↗

How much work-related injury and illness is missed by the current national surveillance system?

OBJECTIVE: We sought to estimate the undercount in the existing national surveillance system of occupational injuries and illnesses. METHODS: Adhering to the strict confidentiality rules of the U.S. Bureau of Labor Statistics, we matched the companies and individuals who reported work-related injuries and illnesses to the Bureau in 1999, 2000, and 2001 in Michigan with companies and individuals reported in four other Michigan data bases, workers' compensation, OSHA Annual Survey, OSHA Integrated Management Information System, and the Occupational Disease Report. We performed capture-recapture analysis to estimate the number of cases missed by the combined systems. RESULTS: We calculated that the current national surveillance system did not include 61% and with capture-recapture analysis up to 68% of the work-related injuries and illnesses that occurred annually in Michigan. This was true for injuries alone, 60% and 67%, and illnesses alone 66% and 69%, respectively. CONCLUSIONS: The current national system for work-related injuries and illnesses markedly underestimates the magnitude of these conditions. A more comprehensive system, such as the one developed for traumatic workplace fatalities, that is not solely dependent on employer based data sources is needed to better guide decision-making and evaluation of public health programs to reduce work-related conditions.

Databases, Factual↗

Reports of birthweight by adolescents and their mothers: comparing accuracy and identifying correlates.

Birthweight is associated with health outcomes throughout the lifespan. Official birthweight records are not always available, and researchers must rely on self-reports for birthweight information. This study evaluates the accuracy of adolescent self-reports of birthweight, using medical records as a standard, and compares it with maternal reports. It also examines potential correlates of accuracy. Respondents are 17-year-old adolescents and their mothers, who participated in a follow-up study of randomly selected samples from newborn discharge lists (1983-85) of two major hospitals in south-east Michigan. Nearly one-quarter of the adolescents stated that they did not know their own birthweight, with males twice as likely as females to respond 'don't know'. In addition, self-reports of birthweight among the remaining adolescents were inaccurate, and accuracy was inversely related to birthweight. While maternal reports of offspring's birthweight are highly accurate across diverse subgroups of the population, adolescent self-reports of birthweight are unlikely to be useful in medical research.

Adolescent↗

Primary care clinicians treat patients with medically unexplained symptoms: a randomized controlled trial.

OBJECTIVE: There is no proven primary care treatment for patients with medically unexplained symptoms (MUS). We hypothesized that a long-term, multidimensional intervention by primary care providers would improve MUS patients' mental health. DESIGN: Clinical trial. SETTING: HMO in Lansing, MI. PARTICIPANTS: Patients from 18 to 65 years old with 2 consecutive years of high utilization were identified as having MUS by a reliable chart rating procedure; 206 subjects were randomized and 200 completed the study. INTERVENTION: From May 2000 to January 2003, 4 primary care clinicians deployed a 12-month intervention consisting of cognitive-behavioral, pharmacological, and other treatment modalities. A behaviorally defined patient-centered method was used by clinicians to facilitate this treatment and the provider-patient relationship. MAIN OUTCOME MEASURE: The primary endpoint was an improvement from baseline to 12 months of 4 or more points on the Mental Component Summary of the SF-36. RESULTS: Two hundred patients averaged 13.6 visits for the year preceding study. The average age was 47.7 years and 79.1% were females. Using intent to treat, 48 treatment and 34 control patients improved (odds ratio [OR]=1.92, 95% confidence interval [CI]: 1.08 to 3.40; P=.02). The relative benefit (relative "risk" for improving) was 1.47 (CI: 1.05 to 2.07), and the number needed to treat was 6.4 (95% CI: 0.89 to 11.89). The following baseline measures predicted improvement: severe mental dysfunction (P<.001), severe body pain (P=.039), nonsevere physical dysfunction (P=.003), and at least 16 years of education (P=.022); c-statistic=0.75. CONCLUSION: The first multidimensional intervention by primary care clinicians led to clinically significant improvement in MUS patients.

Adult↗

Inappropriate ICD therapy: does device configuration make a difference.

INTRODUCTION: Inappropriate implantable cardioverter defibrillator (ICD) therapy (IT) is a common complication in patients with ICD. IT is commonly triggered by supraventricular tachycardias (SVT). Dual chamber ICDs (D-ICDs) may distinguish SVT from ventricular tachycardia/ventricular fibrillation better than single chamber ICDs (S-ICDs) and may be associated with a smaller incidence of IT. METHODS: We reviewed the charts of 386 patients who had an ICD implanted for an AHA class I indication. Intracardiac electrograms were used to classify shocks as either appropriate or inappropriate. RESULTS: Of 295 patients with an S-ICD, 66 (22.3%) received IT, compared to 5 (5.4%) of 91 patients with a D-ICD. The likelihood of being event-free at 1, 2, 3, and 4 years was 96.1%, 96.1%, 96.1%, and 89% for patients with D-ICD and 80.7%, 72.7%, 69.6%, and 66.4%, respectively, for patients with S-ICD (P < 0.001). Multivariate analysis showed no significant association with age, sex, history of atrial fibrillation, history of hypertension, or ejection fraction. SVTs were the commonest cause of IT in our patients. CONCLUSION: Patients with D-ICD are less likely to receive IT as compared to patients with S-ICD.

Aged↗

Implantable cardioverter defibrillator therapy in patients with ischemic or non-ischemic cardiomyopathy and nonsustained ventricular tachycardia.

BACKGROUND: Mortality benefit from implantable cardioverter defibrillator (ICD) therapy in ischemic cardiomyopathy (ICM) with non-sustained ventricular tachycardia (NS-VT) and inducible VT is well defined. Although NS-VT may suggest an increased risk of sudden cardiac death (SCD) in non-ischemic cardiomyopathy (NICM), the role of ICD therapy is unclear. This retrospective study compares follow-up data in these two groups after ICD implantation. METHODS: 153 consecutive patients with ICD implantation for NS-VT were analyzed. ICM patients received an ICD if they had inducible VT at electrophysiology study (EPS). NICM patients did not routinely undergo EPS before ICD implantation. RESULTS: There were 48 patients (33 males) in NICM group and 105 patients (89 males) in the ICM group. Baseline characteristics including mean ejection fraction (EF), distribution in various New York Heart Association (NYHA) classes, and the mean duration of follow up in the two groups were similar. 50% of the patients in the NICM group and 36% in the ICM group received appropriate therapies (p = 0.106). The mean number of appropriate therapies in the two groups were similar (23.3 +/- 56.7 and 22.5 +/- 59.5 respectively, p = NS). The percentage of patients with inappropriate therapies in the two groups were 27% and 23% respectively (p = NS). Patients in the NICM group received appropriate ICD discharges at a greater rate (p = 0.02). CONCLUSION: Patients undergoing ICD implantation for NICM and NS-VT receive appropriate ICD therapy at a greater rate than those implanted for ICM, NS-VT, and a positive EPS. Although these data do not prove survival benefit in NICM, they suggest a beneficial effect.

Adult↗

Estimating mean hospital cost as a function of length of stay and patient characteristics.

Statistical models have been used to assess the influence of clinical and demographic factors on hospital charge and length of stay (LOS). Hospital costs constitute a significant proportion of overall expenditure in health care. With escalating costs, knowing the correlates of LOS and in-hospital cost is important for decisions on allocating resources. However, hospital charge and LOS are correlated. We describe two regression models that permit estimation of mean charges as a function of patient hospital stay and adjust for the influence of patient characteristics and treatment procedures on LOS and charge. In the first model, the mean charge over a specified duration is a weighted average of the expected cumulative charge, with weighting determined by the distribution of LOS. The second model for LOS and charge explicitly accounts for their correlation and yields estimates of the average charge per average LOS. The methods are applied to assess mean charges and mean charge per day by cardiac procedure in a cohort of patients hospitalized for acute myocardial infarction, while adjusting for the impact of patient demographic and clinical factors on LOS and charge. For relatively short hospital stays, and when only total hospital charges are available, these models provide a flexible approach to estimating summary measures on resource use while controlling for the effects of covariates on LOS and charge.

Aged↗

Treating patients with medically unexplained symptoms in primary care.

BACKGROUND: There are no proven, comprehensive treatments in primary care for patients with medically unexplained symptoms (MUS) even though these patients have high levels of psychosocial distress, medical disability, costs, and utilization. Despite extensive care, these common patients often become worse. OBJECTIVE: We sought to identify an effective, research-based treatment that can be conducted by primary care personnel. DESIGN: We used our own experiences and files, consulted with experts, and conducted an extensive review of the literature to identify two things: 1). effective treatments from randomized controlled trials for MUS patients in primary care and in specialty settings; and 2). any type of treatment study in a related area that might inform primary care treatment, for example, depression, provider-patient relationship. MAIN RESULTS: We developed a multidimensional treatment plan by integrating several areas of the literature: collaborative/stepped care, cognitive-behavioral treatment, and the provider-patient relationship. The treatment is designed for primary care personnel (physicians, physician assistants, nurse practitioners) and deployed intensively at the outset; visit intervals are progressively increased as stability and improvement occur. CONCLUSION: Providing a comprehensive treatment plan for chronic, high-utilizing MUS patients removes one barrier to treating this common problem effectively in primary care by primary care personnel.

Anxiety↗

A longitudinal examination of factors related to changes in serum polychlorinated biphenyl levels.

Consumption of sport-caught fish from the Great Lakes is a recognized source of human exposure to polychlorinated biphenyls (PCBs). Understanding temporal changes in PCB body burden is crucial for evaluating exposure levels and augmenting validity of studies investigating their relationship to adverse health effects. Using data collected from 1980 to 1995, we evaluated longitudinal changes in serum PCB levels among 179 fisheaters and non-fisheaters of the Michigan Fisheater Cohort. Participants identified as fisheaters in 1980 ate 26 lb or more of sport-caught fish per year, whereas non-fisheaters ate less than 6 lb per year. We found a monotonic decline in serum PCB levels among all participants from a mean value of 24 ppb in 1980 to 12 ppb in 1994. This was paralleled by an 83% decrease in mean fish consumption among all participants over the same period. We combined demographic, lifestyle, and fish consumption information with PCB data and evaluated the data using regression models to identify predictors of PCB body burden over a 16-year period. Results of the mixed-effects linear regression model suggest that consumption of Lake Michigan fish before 1980, amount of sport-caught fish eaten in the past year, age, and year of data collection were significant determinants of current PCB body burden over the 16-year study period. PCB levels were particularly elevated for males who were classified as fisheaters in 1980, which may reflect higher levels of sport-caught fish consumption compared with female fisheaters.

Adult↗

Patterns of psychotropic medication use in very young children with attention-deficit hyperactivity disorder.

Psychotropic medications are increasingly used for very young children. Patterns of use in a well-described group of children 3 years and younger with a diagnostic label of attention-deficit hyperactivity disorder (ADHD) reveal both reasons to use such medications and concerns about how these medications are used. Of 223 children with ADHD, more than half (n = 127) received psychotropic medications in an idiosyncratic manner, both in the specific medication and in use over time. Almost half of the children who were medicated did not have opportunities for monitoring as often as every 3 months, despite the fact that more than half received psychotropic medications for 6 months or longer. Children with comorbid mental health conditions and chronic health conditions were at greater risk for receiving psychotropic medications. These patterns of use demonstrate a compelling need for guidance in psychopharmacological treatment of very young children.

Attention Deficit Disorder with Hyperactivity↗

Minor acute illness: a preliminary research report on the "worried well".

OBJECTIVES: Our objectives were to determine how patients who make frequent use of the medical system (high users) with medically unexplained symptoms met our chart-rating criteria for somatization and minor acute illness and what the stability of such diagnoses were over time. STUDY DESIGN: A chart review was performed at baseline and 1 and 2 years; we re-rated the charts of patients initially rated as having somatization, as well as a 15% sample of those with minor acute illness. POPULATION: We obtained a random sample of high-use patients (= 6 visits/year) aged 21 to 55 years who were identified from the management information system. OUTCOMES: We measured chart review designations as organic disease, somatization, or minor acute illness. RESULTS: Among 883 high users at baseline, 35% had organic diseases; 14% had somatization; and 51% had minor acute illness as their primary problems. No patients with initial minor acute diagnoses were reclassified as having somatization 1 or 2 years later, and all but 2 patients had minor acute illness in 1 or both follow-up years. CONCLUSIONS: Minor acute illness was more common among high users than somatization and organic diseases combined. It has not previously been studied but probably has been recognized by clinicians as the "worried well." Diagnoses of somatization were unstable over 2 years follow-up, while minor acute diagnoses were stable, supporting the latter as a valid entity.

Adult↗

Using nurse practitioners to implement an intervention in primary care for high-utilizing patients with medically unexplained symptoms.

Patients with medically unexplained symptoms (MUS) often are a source of frustration for clinicians, and despite high quality biomedical attention and frequent diagnostic tests, they have poor health outcomes. Following upon progress in depression treatment approaches, we developed a multidimensional treatment protocol for deployment by primary care personnel. This multi-faceted intervention for MUS patients emphasized cognitive-behavioral principles, the provider-patient relationship, pharmacological management, and treating comorbid medical diseases. We deployed it in an HMO using nurse practitioners (NP) to deliver the intervention to 101 patients, while 102 controls continued to receive medical care from their usual primary care physician. Successful deployment of the intervention required training the NPs, continuing support for the NPs in their management of this difficult population, and establishing strong communication links with the HMO. This paper addresses the practical considerations of using primary care personnel to implement a complex intervention in primary care, and it includes a discussion of special challenges encountered as well as solutions developed to overcome them.

Adolescent↗

Exploration of DSM-IV criteria in primary care patients with medically unexplained symptoms.

OBJECTIVES: Investigators and clinicians almost always rely on Diagnostic and Statistical Manual of Mental Disorder, 4th edition's (DSM-IV) somatoform disorders (and its derivative diagnoses) to characterize and identify patients with medically unexplained symptoms (MUS). Our objective was to evaluate this use by determining the prevalence of DSM-IV somatoform and nonsomatoform disorders in patients with MUS proven by a gold standard chart review. METHODS: In a community-based staff model HMO, we identified subjects for a clinical trial using a systematic and reliable chart rating procedure among high-utilizing MUS patients. Only baseline data are reported here. The World Health Organization Composite International Diagnostic Interview provided full and abridged DSM-IV diagnoses. Patients with full or abridged DSM-IV somatoform diagnoses were labeled "DSM somatoform-positive," whereas those without them were labeled "DSM somatoform-negative." RESULTS: Two hundred six MUS patients averaged 13.6 visits in the year preceding study, 79.1% were females, and the average age was 47.7 years. We found that 124 patients (60.2%) had a nonsomatoform ("psychiatric") DSM-IV diagnosis of any type; 36 (17.5%) had 2 full nonsomatoform diagnoses, and 41 (19.9%) had >2; 92 (44.7%) had some full anxiety diagnosis and 94 (45.6%) had either full depression or minor depression diagnoses. However, only 9 of 206 (4.4%) had any full DSM-IV somatoform diagnosis, and only 39 (18.9%) had abridged somatization disorder. Thus, 48 (23.3%) were "DSM somatoform-positive" and 158 (76.7%) were "DSM somatoform-negative." The latter exhibited less anxiety, depression, mental dysfunction, and psychosomatic symptoms (all p <.001) and less physical dysfunction (p = .011). Correlates of this DSM somatoform-negative status were female gender (p = .007), less severe mental (p = .007), and physical dysfunction (p = .004), a decreased proportion of MUS (p <.10), and less psychiatric comorbidity (p <.10); c-statistic = 0.77. CONCLUSION: We concluded that depression and anxiety characterized MUS patients better than the somatoform disorders. Our data suggested radically revising the somatoform disorders for DSM-V by incorporating a new, very large group of now-overlooked DSM somatoform-negative patients who were typically women with less severe dysfunction.

Anxiety Disorders↗

A method for rating charts to identify and classify patients with medically unexplained symptoms.

BACKGROUND: As part of conducting a randomized control trial (RCT) to treat chronically high utilizing patients with medically unexplained symptoms (MUS), we developed the chart rating method reported here to identify and classify MUS subjects. METHOD: Intended at this point only as a research tool, the method is comprehensive, uses explicit guidelines, and requires clinician raters. It distinguishes primary organic disease patients from those with primary MUS, quantifies medical comorbidities in primary MUS patients, and also distinguishes subgroups among MUS patients that we call somatization (resembles DSM-IV somatoform disorders) and minor acute illness (MAI) which differs from DSM-IV somatoform definitions. Scoring rules are used to generate the diagnoses above. The rules may be set according to the investigator's needs, from highly sensitive to highly specific. RESULTS: We found high levels of agreement with the gold standard for MUS vs. organic disease (97.6%) and among raters for the key individual chart elements rated (92-96%). The method identified 206 MUS subjects and the extent of their medical comorbidities for entry into a RCT. It also identified somatization and MAI; the latter supports the validity of this newly reported MAI syndrome. CONCLUSION: We concluded that this method offered research potential for identifying MUS patients, for quantifying their medical comorbidities, and for classifying MUS subgroups.

Comorbidity↗