R2 (REVISED MANUSCRIPT BLUE 200208-877OC) ONLINE DATA SUPPLEMENT - ASTHMA INTERVENTION PROGRAM PREVENTS READMISSIONS IN HIGH HEALTHCARE UTILIZERS Mario Castro, M.D., M.P.H. Nina A. Zimmermann R.N. Sue Crocker R.N. Joseph Bradley Charles Leven, Ph.D. Kenneth B. Schechtman, Ph.D. 1
METHODS - Extended Version Patients All patients admitted to Barnes-Jewish Hospital with the primary admitting diagnosis of asthma were screened for participation from September 1996 to July 1999. Patients were eligible for the study if they had a physician diagnosis of asthma of at least 12 months duration, were from 18 65 years of age, and hospitalized at Barnes-Jewish Hospital. Patients were required to have a forced expiratory volume in one second (FEV 1 ) to forced vital capacity (FVC) ratio less than 80%. Patients who met these criteria and had a history of one or more hospitalization in the twelve months prior to evaluation were eligible. The criteria for exclusion from the study included: chronic bronchitis, emphysema, or congestive heart failure diagnosed by the primary physician; a terminal condition with anticipated survival of less than one year; dementia or serious psychiatric illness, such as schizophrenia or personality disorder; planned discharge to a long-term care facility, anticipated early discharge of less than 24 hours, not allowing enough time to complete the intervention, or refusal to participate by the patient or physician of record. The study was approved by the Human Studies Committee of Washington University School of Medicine. All patients gave informed consent before entry into the study. A total of 828 patients were admitted with a primary diagnosis of asthma during the period of enrollment. Of these, 732 were excluded for the following reasons: 230 were discharged in less than 24 hours, 201 had a diagnosis other than asthma, 122 had no previous hospitalization within the last twelve months, 29 patients were not mentally stable, and 28 patients refused to participate prior to randomization. An additional 122 2
patients were excluded if they left against medical advice, were under the care of one of the investigators, did not meet age criteria or unable to give consent, or the patient s primary physician refused to allow the patient to enroll or could not be contacted for approval. Therefore, 96 patients were eligible for randomization. Study Design and Intervention The study consisted of a randomized, controlled prospective trial investigating the use of an asthma nurse specialist to provide a multi-faceted approach to asthma care for high-risk inpatients who met the study criteria. Three consecutive nurses provided the intervention during the study. The study patients were randomly assigned to the intervention or usual care group in a blind selection procedure using a pre-randomized assignment in a sealed envelope. The patients and healthcare team were not blinded to treatment assignment due to the nature of the intervention. The usual care group received the normal care provided by their private primary care physician. Asthma education was provided to the usual care group by the hospital respiratory therapist and nurse including asthma medication dosing, action and side effects, as well as inhaler technique and peak flow monitoring. The usual care group received written discharge instructions from the hospital nurse stating the patient s discharge medications and physician follow-up information but did not include an asthma action or management plan. No nursing care was provided to the usual care group by the study nurses other than obtaining study data and the performance of baseline spirometry. The study intervention consisted of the following multi-faceted approach: 1) The asthma nurse specialist reviewed the individual treatment plans with the patients. The 3
nurse made suggestions to the primary physician regarding potential changes to the treatment plan, including simplification or consolidation, in accordance with the National Asthma Education and Prevention Program II[E1]. 2) Completion of a daily Asthma Care flow sheet while in the hospital which included a symptom score, pulmonary functions (including peak expiratory flow), current asthma medications, and any pertinent recommendations. The purpose of this Asthma Care flow sheet was to provide direct communication from the nurse specialist to the primary physician on the status of the patient. 3) Provision of asthma education appropriate to the patient s education, motivation, and cultural beliefs. This included individual instruction using tailored asthma education which included identifying triggers, early and late warning signs, medications and delivery technique, use of a spacer, peak flow monitoring, how to implement environmental control measures, assessing need for allergy skin testing, smoking cessation counseling, and importance of follow-up care. As many sessions as possible were provided to the patient until they were discharged (on average 2 sessions). 4) Provision of psychosocial support and screening patients for professional counseling. In the majority of cases, psychosocial support was provided by the asthma nurse specialist directly through verbal and written communication. If there was an important psychosocial issue that could interfere with asthma control and it was beyond the asthma nurse s expertise, the patient was referred to a social worker or psychiatric nurse specialist. 5) Establishing an individualized written Asthma Self-Management plan in conjunction with the treating physician. 6) Consultation with social service professionals when necessary to facilitate discharge planning. 7) Provision of outpatient follow-up through telephone contacts (on average 5.8 telephone contacts per patient, range 0-24) 4
and follow-up appointments with primary physician, as necessary. The patient s asthma control was assessed at these subsequent contacts and the primary physician was contacted if necessary. In some patients, a home visit (on average 0.4 home visits per patient, range 0-3) was necessary for patients who were unavailable by phone, to establish trust, and to evaluate for potential environmental or social factors which might be contributing to poor asthma control. Study endpoints All analysis was conducted with the intention-to-treat principle with the primary endpoint being readmission due to asthma within 360 days. Secondary endpoints included total readmissions, emergency department visits, quality of life, direct and indirect healthcare costs, lost school or work days, cumulative number of days of hospitalization, and the number of refills of asthma medications within 360 days. Data Collection Detailed data were collected at entry into the study by the asthma nurse specialist, including demographics, medical history, and information regarding the patients asthma history, including age at onset and diagnosis, previous hospitalizations, emergency department visits, environmental exposures and triggers, and medications. Spirometry was performed at enrollment, including measurement of FEV 1, FVC, and peak expiratory flow, in accordance with American Thoracic Society recommendations[e2]. The values expressed are reported in absolute values and as a percentage of the predicted normal values for each patient based on age, sex, height, and race. Predicted normal values were obtained from standard references[e3, 4]. Demographic, health care utilization, missed school/work days, and cost data were updated at 90 and 180 days based upon patient s 5
cost logs (described below). All hospitalizations, emergency department, and physicians visits were corroborated by the patient s medical records. Cost analysis Costs were estimated using cost logs which were collected contemporaneously by all patients during the 180 day enrollment period. The cost logs contained detailed information regarding health care utilization, medications, and hours spent by paid and unpaid healthcare givers. The cost logs were verified by the study nurse during follow up visits and the amount of time spent providing the intervention was documented (excluding time spent for research purposes). An hourly rate of $35 was chosen as the cost of nursing time and $15 for paid or unpaid caregiver time. The cost of a lost work day was calculated at $75 per day for both the patient and family caregiver. The cost for a physician visit was calculated at $40 per visit. The cost of allergy skin testing or immunotherapy was set at $400 each (prevailing rates in the St. Louis area). Costs for hospital admissions were based on allowed reimbursements according to standard codes for each diagnosis-related group (DRG). Direct medical costs included hospitalizations, emergency department visits, physician visits, nurse or paid caregiver home care, allergy skin tests/immunotherapy, and asthma medications. Indirect costs included the cost of lost work days by the patient or family caring for the patient, and nonprofessional or other paid help. All costs were adjusted to 1999 dollars. Quality of life Quality of life was measured using a disease-specific measure, the Asthma Quality of Life Questionnaire, at entry into the study and at 6 months following the initial hospitalization[e5]. This questionnaire contains 32 questions with four different domains: 6
activity limitation, asthma symptoms, emotional function, and environmental exposure. The activity domain is individualized to five different activities pertinent to that patient. Each question for recall of impairment during the previous two weeks using a 7- point scale. Overall quality of life score is estimated from the unweighted mean score of all the items. Previous studies have shown this questionnaire to be valid as an evaluative and discriminative instrument[e5, 6]. Statistical analysis T-tests and chi-square tests were used to compare variables between groups unless otherwise noted. However, because of the skewed nature of variables such as the number of days in the hospital and the number of emergency department visits, Wilcoxon's test was sometimes used as an alternative to the t-test. Stepwise logistic regression was used to identify variables that had an independent association with being readmitted at least two times within a year of the initial hospitalization. Variables entered into the model as potential predictors included the study group and all variables that were significantly associated with repeat hospitalization. These included the age of the patient, the duration of asthma, the number of hospitalizations in the previous 12 months, and FEV 1 (percent predicted). A logrank test was used to perform between group comparisons of the survival curves measuring time to the first readmission. Summary data on continuous variables are expressed as mean + standard deviation. All data analyses were performed using SAS software (SAS Institute, Cary, N.C.). 7
REFERENCES E1. National Asthma Education and Prevention Program: Expert Panel Report II: Guidelines for the diagnosis and management of asthma. National Institutes of Health; National Heart, Lung, and Blood Institute, 1997. E2. American Thoracic Society. Standards for the diagnosis and care of patients with chronic obstructive pulmonary disease (COPD) and asthma. Am Rev Respir Dis 1987; 136: 225. E3. Knudson RJ, Lebowitz MD, Holberg CJ, Burrows B. Changes in normal maximal expiratory flow-volume curve with growth and aging. Am Rev Respir Dis 1983; 127: 725-734. E4. Miller A. Pulmonary function tests in clinical and occupational lung disease. Orlando, Fla:: Grune and Stratton, 1986; 146-48. E5. Juniper E, Guyatt G, Ferrie P, Griffith L. Measuring quality of life in asthma. Am Rev Respir Dis 1993; 147: 832-838. E6. Juniper E, Guyatt G, Willan A, Griffith L. Determining a minimal important change in a disease-specific quality of life questionnaire. J Clin Epidemiol 1994; 47: 81-87. 8