A Randomized Controlled Trial of Follow-up of Patients Discharged From the Hospital Following Acute Asthma*

Original Research ASTHMA A Randomized Controlled Trial of Follow-up of Patients Discharged From the Hospital Following Acute Asthma* Best Performed by Specialist Nurse or Doctor? James A. Nathan, MRCP; Linda Pearce, MSc, RN; Carol Field, RN; Nina Dotesio-Eyres, RN; Linda D. Sharples, PhD; Fay Cafferty, Mmath; and Clare M. Laroche, FRCP Objective: To evaluate whether follow-up of patients recently discharged from the hospital as a result of acute asthma can be adequately provided by a respiratory specialist nurse compared to a respiratory doctor. Design: Single center, prospective, randomized controlled trial. Setting: District general hospital in the United Kingdom. Participants: One hundred fifty-four of 373 eligible patients admitted with acute asthma were enrolled into the study from October 2000 to October 2003. All patients > 16 years of age were eligible for the study. Patients with COPD were excluded. Intervention: Patients were randomly assigned to receive an initial 30-min follow-up clinic appointment within 2 weeks of hospital discharge with either a specialist nurse or respiratory doctor. This comprised a medical review, patient education, and a self-management asthma plan. Further follow-up was then arranged as was deemed appropriate by the corresponding doctor or nurse. All patients were asked to attend a 6-month appointment. Measurements: The primary outcome was the number of exacerbations within 6 months of hospital admission. Secondary outcome variables were change in peak flow, quality of life (using the St. George Respiratory Questionnaire (SGRQ) and the Asthma Questionnaire 20 [AQ20]), and clinic attendance. Results: Outcome data were available for 66 patients in the doctor group and 70 patients in the nurse group. There was no difference in the number of patients with exacerbations in the nurse group compared to the doctor group (45.6% vs 49.2%; odds ratio, 0.86; 95% confidence interval [CI], 0.44 to 1.71; p 0.674). However, a significant proportion of patients in both groups had exacerbations despite hospital outpatient follow-up. There was no difference in quality of life (p 0.285; mean difference, 0.78; 95% CI, 0.64 to 2.19 for the AQ20; and p 0.891; mean difference, 1.08; 95% CI, 5.05 to 7.21 for SGRQ) or change in peak flow (mean difference between nurse and doctor groups, 1.39 (95% CI, 3.84 to 6.63; p 0.122) at 6 months. Conclusions: Follow-up care by a nurse specialist for patients admitted with acute asthma can be delivered equivocally with comparable safety and effectiveness to that given by a doctor. (CHEST 2006; 130:51 57) Key words: asthma; randomized controlled trial; respiratory nurse specialist Abbreviations: AQ20 Asthma Questionnaire 20; BTS British Thoracic Society; CI confidence interval; SGRQ St. George Respiratory Questionnaire Acute asthma exacerbations remain a major cause of hospital admissions. 1,2 British Thoracic Society (BTS) asthma guidelines 3 recommend that all patients admitted to the hospital with an exacerbation should be followed up within 6 months. In the United Kingdom, this follow-up is commonly performed in medical clinics by consultant doctors or, frequently, by doctors in training. The purpose of the follow-up consultation is to review the diagnosis, ensure optimization of medical treatment, and to www.chestjournal.org CHEST / 130 / 1/ JULY, 2006 51

identify and if possible eliminate factors that gave rise to the hospital admission. However, several studies 4 6 have suggested that social and compliance issues are important in patients with poor asthma control. These issues are now increasingly addressed by respiratory nurse specialists. Hospital education, self-management, and outreach programs for asthma For editorial comment see page 8 are now routinely conducted by nurse specialists, but some uncertainty remains over their long-term effectiveness. 7 9 In general practice, nurse specialists can significantly reduce asthma morbidity with nurse-led asthma clinics. 10 Although hospital outpatient clinics conducted by nurse specialists are increasing in frequency, their effectiveness has not been evaluated. We wanted to examine the role of the respiratory nurse specialist in this setting and to compare clinical outcomes with patients managed by a respiratory consultant (doctor). In 1996, a respiratory doctor follow-up clinic was set up at West Suffolk Hospital NHS Trust, which offered a follow-up clinic to all adult patients admitted with an acute asthma exacerbation to be seen within 2 weeks of hospital discharge. This reduced the readmission rate to the hospital. To increase the extent of this service, a nurse specialist also conducted these clinics. In 1999, a pilot study 11 of 85 patients was conducted to assess whether this clinic could safely be run by a respiratory nurse specialist alone. The study found that the readmission rate at 6 months was 4% in the physician patient group compared to 6% in the nurse specialist group. However, this pilot study was not sufficiently powered to show a small difference in exacerbation rate, readmission rate, or quality of life between the two groups. Therefore, a larger, randomized controlled trial was needed. The aim was to assess whether follow-up by a nurse specialist following an acute *From the Department of Respiratory Medicine (Drs. Nathan and Laroche, Ms. Pearce, Ms. Field, and Ms. Dotesio-Eyres), West Suffolk Hospital NHS Trust, Suffolk; Medical Research Council Biostatistics Unit (Dr. Sharples), Institute of Public Health, Cambridge; and Research & Development Unit (Ms. Cafferty), Papworth Hospital NHS Trust, Papworth Everard, Cambridge, UK. Funding was granted by the NHS Executive (Eastern Region). All researchers are independent from the funders of the study. Manuscript received April 29, 2005; revision accepted January 24, 2006. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal. org/misc/reprints.shtml). Correspondence to: Clare M. Laroche, FRCP, Department of Respiratory Medicine, West Suffolk Hospital NHS Trust, Bury St Edmunds, Suffolk, IP33 2QZ, UK; e-mail: clare.laroche@ wsh.nhs.uk DOI: 10.1378/chest.130.1.51 asthma admission was as effective as that by a respiratory doctor. Follow-up in the study was for a 6-month period. Materials and Methods All patients 16 years of age and admitted to the hospital with acute asthma between October 2000 and October 2003 were eligible for the trial. Asthma was diagnosed by BTS criteria. 3 Patients were excluded if they had COPD or were unable or unwilling to consent to the study. Patients attending the emergency department but not being admitted were not included in the study, as they would generally have had a milder attack (peak expiratory flow 50% of predicted or best or 60% after nebulization) and would not normally be offered a routine follow-up appointment in the respiratory clinic. Recruitment was undertaken by an independent clinical research nurse who identified all patients shortly after hospital admission and visited them prior to discharge to discuss the study. After written consent was obtained, the patients were randomly assigned using a randomized envelope system administered by the clinical research nurse, to be seen by the respiratory doctor or a respiratory specialist nurse at follow-up from the hospital admission. The respiratory nurse specialist had experience as a nurse in primary care prior to several years as a respiratory nurse specialist in secondary care. The nurse was a qualified nurse practitioner and had received specialist training in acute and chronic asthma management. Their formal training included The Education for Health Asthma Diploma (a UK national course) and a Master of Science degree (dissertation on acute asthma management). The outpatient specialists were blinded as to which follow-up group the patient was assigned until hospital discharge. Ethical approval was given by West Suffolk Research and Ethics Committee. Inpatient Management Patients were admitted with asthma from the emergency department according to BTS guidelines and were managed by a general physician on a respiratory ward according to an agreed integrated care pathway. However, if appropriate, advice was sought from the respiratory doctor responsible for the patient s management. Outpatient Management All patients enrolled into the trial received an initial 30-min hospital follow-up appointment at 2 weeks after discharge with the respiratory doctor or specialist nurse. Fifteen-minute follow-up appointments were then arranged as believed necessary by either specialist. There were no set criteria for adding follow-up appointments. All patients were asked to attend a 6-month follow-up appointment. The consultations in either arm of the study consisted of an evaluation of the events leading to the hospital admission; an assessment of the patients understanding of their asthma; initiation or reinforcement of asthma education; an assessment of their understanding of asthma therapy; assessment of inhaler technique; a self-management plan; and appropriate change in asthma medication. The specialist nurse prescribed independently according to an agreed asthma protocol (patient group directive). The self-management plan provided was based on changes in peak flow and symptoms. Data Collection Peak flow was recorded as a percentage of predicted value or previous best recorded in the hospital, at first follow-up, and at 6 52 Original Research

months. Patients were given a diary card for the 6-month follow-up to record twice-daily peak flow, any medication change, emergency treatment, or exacerbations. An exacerbation was defined as a drop in peak flow 30% of predicted or best predicted, requiring any of the following: increased inhaled corticosteroids, emergency nebulization, or a course of oral corticosteroids. Details of any exacerbations were obtained from the patient diary card, attendance records in the emergency department, and general practice records. No inconsistencies were found. A few patients in the study had home nebulizers and were able to self-administer bronchodilators during an exacerbation. However the use of home nebulization was not being actively encouraged during the period of the study. Asthma medication was recorded at hospital discharge, at the 2-week follow-up, and at the 6-month follow-up. Data collection was performed by an independent research assistant who was unaware of the group to which the patient was allocated. In addition, in a separate analysis, details of hospital appointments offered and whether the patient attended, cancelled, or did not attend (or indeed whether the clinic appointment was cancelled by the clinician) were obtained from the hospital information system. This outcome was included to assess whether type of professional seen had any impact on the likelihood of a patient attending the appointment. Quality of Life Patients were asked to complete the Asthma Questionnaire 20 (AQ20) quality of life questionnaire and the St. George Respiratory Questionnaire (SGRQ) during hospital admission and at the 6-month assessment. The SGRQ has three dimensions: symptoms, activity, and impacts. 12 These can be summed to give a total score (expressed as a percentage). High scores represent a poor quality of life. The AQ20 is a simpler, shortened version of the SGRQ. 13 Comparison of the two questionnaires will be reported separately. Outcomes The primary outcome was to compare the number of acute exacerbations within 6 months of hospital discharge between the two groups. The change in peak flow as a percentage of predicted or previous best at 6 months and differences in quality of life were also evaluated. Four possible clinic outcomes were also compared between the groups: patient attended, patient cancelled, patient did not attend, or clinician cancelled. Statistical Analysis Sample size was calculated using methods described by Jones et al 14 to demonstrate equivalence (to within 15%) in the primary outcome. An exacerbation rate of 10% was assumed; 168 patients were needed to give a power of 80% with significance level of 0.05. Note that since this is an equivalence trial, the emphasis of the analysis should be on confidence intervals (CIs) rather than p values because the failure to detect a difference via significance testing does not necessarily imply equivalence. However, the CI provides a range of values for the possible magnitude of difference between the two groups, and we can be reasonably confident that the true difference lies within this range. Thus, if all points in the CI correspond to a difference that is not clinically important (for example 15% for the exacerbation rates), we can conclude that the groups are equivalent in this respect. 14 The number of patients with exacerbations and readmissions were tabulated against group, and the odds ratio for the nurse compared to the doctor was calculated, with 95% CIs. Exacerbation rates are expressed as the number of exacerbations per patients for descriptive purposes. The number of exacerbations per patient was tabulated against study group, and Pearson s 2 statistic was used to assess the association. Poisson regression with a log-link function was used to model the number of exacerbations. The nurse/doctor group was included in the model, and the exponential of the coefficient for this term was used to estimate the relative exacerbation rate for nurse-led follow-up compared with doctor-led follow-up. Significance levels for these terms are taken from the likelihood ratio test, comparing the model without this term to the model including it. Similar models were fitted to assess the effect of nurse-led follow-up and clinic appointments made. The number of clinics attended was tabulated against group and compared using a 2 test. The number of clinics attended was analyzed using Poisson regression. In these models, terms for clinic outcome, group, and outcome/group interaction were included. The interaction term was of primary interest to establish if, for each outcome, different counts could be expected from the two groups. A likelihood ratio test was used to compare the full model to the model incorporating only differences between outcomes. Two-sample t tests were used to compare the groups for changes from baseline in the AQ20 and in the dimensions of the SGRQ. The Mann- Whitney U test was used to compare the groups for change in peak flow. Results One hundred fifty-four patients were recruited over 3 years from 373 adults admitted with asthma. The most common reason for exclusion was that patients were admitted for 24 h or the clinical researcher was not notified of the admission. Other reasons for exclusion are shown in Figure 1. Seventysix patients were randomized to the doctor group, and 78 patients were randomized to the specialist nurse group. Analysis was by intention to treat. At clinic follow-up, 13 patients were found not to have asthma (many patients were not seen by a respiratory physician during their hospital stay), 4 patients withdrew from the study, and 1 patient was excluded because of participation in the pilot study. Thus, 66 patients (86.8%) in the doctor group and 70 patients (89.7%) in the nurse group were analyzed. When measurements were missing for particular variables, the patients were not included in that part of the analysis. The median age was 33 years (range, 17 to 83 years) in the nurse group, compared to 37 years (range, 17 to 91 years) in the doctor group (p 0.17). The median time from inpatient admission to hospital discharge was 3 days in both groups (range, 1 to 14 days; p 0.23). Similar numbers of patients had a general practitioner attendance or a referral to a psychologist in both groups. Exacerbations Complete data were available for 65 patients in the doctor group and 68 patients in the nurse group. Thirty-two patients (49.2%) in the doctor group and www.chestjournal.org CHEST / 130 / 1/ JULY, 2006 53

Figure 1. Patient flow through the study. 31 patients (45.6%) in the nurse group had exacerbations over the 6-month follow-up period, an odds ratio of 0.86 (95% CI, 0.44 to 1.71; p 0.674). Altogether, there were 174 exacerbations recorded, 76 in the doctor group and 98 in the nurse group. There was no association between group and the number of exacerbations (p 0.368, 2 test). The number of exacerbations per patient are shown in Figure 2; 10.5% (14 of 133 patients) had four or more exacerbations. The mean number of exacerbations per patient was 1.44 (98 exacerbations in 68 patients) in the nurse group, compared with 1.17 (76 exacerbations in 65 patients) in the doctor group. Using Poisson regression, this gives a relative risk of 1.23 (95% CI, 0.91 to 1.66; p 0.368). Figure 3 shows a breakdown of exacerbation types. Thirteen patients were readmitted with asthma exacerbations in the 6 months, resulting in 17 readmissions to the hospital, 12 in the doctor group and 5 in the nurse group. There was no significant difference in the number of patients readmitted between the groups (p 0.336). The mean number of hospital readmissions per patient was 0.07 in the nurse group (5 readmissions in 68 patients) and 0.18 in the doctor group (12 readmissions in 65 patients). Using Poisson regression, the relative risk of readmission was 0.40 (95% CI, 0.14 to 1.12; p 0.09). Figure 2. The number of exacerbations per patient in each study group. 54 Original Research

group, compared to a 0.31 increase (SD 3.53) in the doctor group in the 6-month period. The difference, 0.78 (95% CI, 0.64 to 2.19), was not significant (p 0.285). There was a mean improvement in the SGRQ score of 3.94% (SD 14.34) in the nurse group, compared with an improvement of 5.02% (SD 16.43) in the doctor group. This difference of 1.08 (95% CI, 5.0 to 7.2) was not significant (p 0.727). Each of the three components of the SGRQ (symptoms, activity, and impacts) were also assessed individually in this way, and no differences were found. Figure 3. The number of patient exacerbations according to type. Emergency nebulization, defined as the use of rescue nebulization in accident and emergency departments, general practice, or by ambulance paramedics, was required 35 times (for 17 different patients) in the nurse group, compared to 16 times (for 10 different patients) in the doctor group. To examine this further, we compared those patients who required any form of emergency treatment (hospital admission or emergency nebulization) for the exacerbation; this totaled 30 patients. The mean number of exacerbations per patient requiring emergency treatment was 0.59 in the nurse group and 0.43 in the doctor group. From Poisson regression, the relative risk of requirement for emergency treatment was 1.37 (95% CI, 0.84 to 2.21), demonstrating no significant difference between the groups. We also considered exacerbations requiring an additional intervention (all those except an increase in inhaled corticosteroids, for instance IV or oral steroids). Fifty-two patients required an additional intervention during an exacerbation, 27 patients (51.9%) in the nurse group and 25 patients (48.1%) in the doctor group (p 0.572). The mean number of exacerbations requiring additional treatment per patient was 1.18 in the nurse group compared to 0.91 in the doctor group (relative risk, 1.30; 95% CI, 0.93 to 1.81). Quality of Life Only 52 patients in the doctor group and 49 patients in the nurse group completed the quality of life questionnaires. The remaining participants declined to complete the final 6-month questionnaires despite reminders being sent. In the AQ20, there was a mean drop of 0.47 (SD 3.73) in the nurse Change in Peak Flow We compared the maximal peak flow measurement at first hospital follow-up with the 6-month measurement (best of actual or predicted). There was a mean drop of 2.53% (SD 11.5) in the doctor group and 3.92% (SD 12.4) in the nurse group. There was no significant difference in change in peak flow between the two groups (mean difference, 1.39%; 95% CI, 3.84 to 6.63; p 0.122). Clinic Outcomes Data were available for all 136 patients. The mean number of follow-up clinic appointments arranged was similar in both groups: 3.39 (237 appointments in 70 patients) in the nurse group and 3.32 (219 appointments in 66 patients) in the doctor group (relative risk, 1.02; 95% CI, 0.85 to 1.23). However, patients attended fewer nurse clinics compared to doctor clinics. The mean number of clinics attended was 1.97 (130 clinics in 66 patients) in the nurse group and 2.23 (147 clinics in 66 patients) in the doctor group (relative risk, 0.88; 95% CI, 0.70 to 1.12; p 0.011). This appeared to be due to cancellation of clinics by the specialist nurse rather than cancellation or nonattendance by the patient. More clinics were cancelled by the clinical nurse specialist rather than by the doctor. The mean number of clinics cancelled by the nurse was 0.32, compared to 0.08 cancelled by the doctor (relative risk, 4.20; 95% CI, 1.6 to 11.0; p 0.004). There was a trend toward patients in the nurse group being more likely to cancel the clinic appointment (relative risk, 1.65; 95% CI, 1.30 to 2.08; p 0.052) but no difference in the number of clinics not attended (relative risk, 0.90; 95% CI, 0.54 to 1.48; p 0.70). Discussion This study demonstrates that an appropriately trained respiratory specialist nurse, with regard to the follow-up of patients after hospitalization for an acute asthma exacerbation, may provide equivalent www.chestjournal.org CHEST / 130 / 1/ JULY, 2006 55

asthma care to that of a respiratory physician. This is the first study to directly compare physician-led and nurse-led care in a specialist outpatient setting. The primary outcome, comparing the number of exacerbations between the groups, showed no significant difference between the two groups. Analysis of subgroups of exacerbation types was pursued to further evaluate whether any subtle differences occurred (Fig 3). The proportions regarding hospital readmission and emergency nebulization appeared different between the groups, but these subgroups were too small for formal statistical analysis. To further compare the groups, we looked at those requiring emergency treatment that included the use of emergency nebulization (in accident and emergency departments, general practice, or ambulances) and hospital readmission. This showed no significant difference between the groups. This is also true when including those who required outpatient treatment with oral corticosteroids. This demonstrates equivalence between the doctor-treated and nursetreated patients in the number and severity of exacerbations. The number of clinics was not significantly different between the groups. On subgroup analysis, patients were more likely to attend to see the doctor, and more clinics were cancelled by the nurse. However, over a 6-month period, this difference is of doubtful clinical significance, as this does not appear to have resulted in excess exacerbation rates. Quality of life assessment is important to consider in addition to exacerbation rates. The AQ20 has been compared to the SGRQ and the Asthma Quality of Life Questionnaire and has been shown to be quicker to complete and show good correlation. 13 There was no evidence of a difference between the groups. This quality of life assessment, in conjunction with the exacerbation rates between the groups, demonstrates that an appropriately trained specialist nurse can perform as well as that of the respiratory physician in a well-defined area. The strengths of our study include complete data for 88% of those enrolled into the trial. Of the 136 patients who completed the study, 133 patients (98%) had complete primary outcome data, so that bias due to missing responses should be negligible. For other outcomes (peak flow and quality of life measures), a larger amount of data were missing. On investigation, there is some evidence that the group of patients without responses are a younger group who had fewer exacerbations during the 6-month period compared with the rest of the study population. Therefore, this may be a source of bias in the study. The data collectors were blinded to the randomization procedure, and bias was also reduced because the data analyst was unaware of group allocation. The effectiveness of the nurse specialist has been directly compared to that of the physician and subgroups of exacerbation type analyzed to identify minor differences between the groups. Only 154 patients were enrolled from 373 potential patients. This potentially could cause bias, especially as patients who were discharged within 24 h (presumably because of a milder attack) were less likely to be recruited to the study. In this study, the respiratory nurse specialist had experience managing asthma in both primary and secondary care settings and regularly taught asthma management to a range of health professionals. The structure of the outpatient clinic was agreed before commencing the trial, and both the nurse and the doctor followed national and international guidelines for management and treatment. We believe the study is applicable to respiratory nurse specialists as a whole with appropriate experience and supervision. Overall, 47.4% of the patients in our study group had an exacerbation in the 6 months of follow-up. This is higher than reported in other studies 15 but may reflect the comprehensive way the details of exacerbations were obtained. The apparently high exacerbation rate may also reflect the fact that our study included patients with more severe asthma, due to the problems of recruiting patients who were discharged quickly (and who may have had milder attacks). However, the high exacerbation rate was not associated with a correspondingly high hospital readmission rate, which is a recognized outcome measure of asthma care. 16 Over the 6-month follow-up period, 12.3% and 7.4% of patients in the doctor-led and nurse-led groups, respectively, were readmitted with an acute asthma attack. This compares favorably with other studies. 7,8,17,18 The number of patients recruited to the study was less than planned, and this led to odds ratios for exacerbation rates that were less precise and only a 60% chance of ruling out clinically significant increases in exacerbation rates. Thus, although there were no significant differences between nurse-led and doctor-led care in the main outcomes, some of the CIs included potentially clinically significant effects. We therefore recommend that this practice be audited to ensure that exacerbation rates remain acceptable. In general practice, specialist nurse asthma clinics have become a major part of asthma care. Although studies 10,19,20 have demonstrated increased asthma knowledge, it is unclear whether hospital admission rates are reduced. Differences may also arise depending on ethnicity. 21 Hospital specialist nurse care has been studied with regard to patient education, self-management, and readmission rates. Inpatient, 56 Original Research

nurse-led education and management programs have been shown to reduce readmissions in children. 17 Self-management plans initiated in hospital with a specialist nurse have improved asthma knowledge and morbidity in adults. This has been shown to reduce the need for contacting health professionals but not necessarily a reduction in readmission rates. 7,8 The role of follow-up by the specialist nurse has been studied with regard to hospital and accident and emergency attendance. Both telephone follow-up and outpatient clinics have been shown to reduce attendance at accident and emergency departments. 9,22 Asthma education programs conducted by a specialist nurse have also been shown to be beneficial. 23,24 It clearly appears that inpatient and outpatient intervention aimed at asthma education and self-management are important in improving asthma care. However, the safety and effectiveness of sole follow-up by a respiratory specialist nurse in patients admitted to hospital with an acute asthma attack have not previously been studied. In patients with bronchiectasis, routine outpatient care delivered by an appropriately trained specialist nurse has been shown to be as safe and effective as doctor-led care. 25 Our study demonstrates that outpatient care can be safely and effectively delivered by an appropriately trained respiratory specialist nurse, using a structured intervention, similar-length outpatient times, and prescribing independently according to a patient group directive, even in patients not previously assessed by a respiratory doctor. This study has important implications for the role of the respiratory specialist nurse, since we have demonstrated that their role can be extended to outpatient care. This may not only help reduce some of the workload that exists for many respiratory doctors but also ensure that effective outpatient care continues. References 1 Lung & Asthma Information Agency. Trends in hospital admissions and asthma deaths from asthma: factsheet 2002/1. Available at: http://www.laia.ac.uk/2002_1/2002_1.htm. Accessed March 1, 2006 2 The burden of lung disease: a statistics report from the British Thoracic Society. London, UK: British Thoracic Society, 2000; 21 34 3 British Thoracic Society. British guideline on the management of asthma. Thorax 2003; 58(Suppl 1):i54 i65 4 Cochrane GM. Compliance and outcomes in patients with asthma. Drugs 1996; 52(Suppl 6):12 9 5 Busse WW, Kiecolt-Glaser JK, Coe C, et al. Stress and asthma. Am J Respir Crit Care Med 1995; 151:249 252 6 Barnes PJ, Woolcock AJ. Difficult asthma. Eur Respir J 1998; 12:1209 1218 7 Morice AH, Wrench C. The role of the asthma nurse in treatment compliance and self-management following hospital admission. Respir Med 2001; 95:851 856 8 Osman LM, Calder C, Godden DJ, et al. A randomised trial of self-management planning for adult patients admitted to hospital with acute asthma. Thorax 2002; 57:869 74 9 Levy ML, Robb M, Allen J, et al. A randomised controlled evaluation of specialist nurse education following accident and emergency department attendance for acute asthma. Respir Med 2000; 94:900 8 10 Dickinson J, Hutton S, Atkin A, et al. Reducing asthma morbidity in the community: the effect of a targeted nurserun asthma clinic in an English general practice. Respir Med 1997; 91:634 40 11 Laroche C, Pearce L, Simpson T, et al. Reducing asthma readmissions: follow up by respiratory doctor or respiratory nurse [abstract]. Thorax 1999; 54(Suppl 3):A53 12 Jones PW, Quirk FH, Baveystock CM. The St. George s Respiratory Questionnaire. Respir Med 1991; 85(Suppl B): 25 31 13 Barley EA, Quirk FH, Jones PW. Asthma health status measurement in clinical practice: validity of a new short and simple instrument. Respir Med 1998; 92:1207 1214 14 Jones B, Jarvis P, Lewis JA, et al. Trials to assess equivalence: the importance of rigorous methods. BMJ 1996; 313:36 9 15 Tattersfield AE, Postma DS, Barnes PJ, et al. Exacerbations of asthma. Am J Respir Crit Care Med 1999; 160:594 599 16 Slack R, Bucknall CE. Readmission rates are associated with differences in the process of care in acute asthma. Qual Health Care 1997; 6:194 198 17 Wesseldine LJ, McCarthy P, Silverman M. Structured discharge procedure for children admitted to hospital with acute asthma: a randomised controlled trial of nursing practice. Arch Dis Child 1999; 80:110 114 18 Castro M, Zimmermann NA, Crocker S, et al. Asthma intervention program prevents readmissions in high healthcare users. Am J Respir Crit Care Med 2003; 168:1095 1099 19 Premaratne UN, Sterne JAC, Marks GB, et al. Clustered randomised trial of an intervention to improve the management of asthma: Greenwich asthma study. BMJ 1999; 318: 1251 1255 20 Jones KP, Mullee MA, Middleton M, et al. Peak flow based asthma self-management: a randomised controlled study in general practice. Thorax 1995; 50:851 857 21 Griffiths C, Foster G, Barnes N, et al. Specialist nurse intervention to reduce unscheduled asthma care in a deprived multiethnic area: the east London randomised control trial for high risk asthma (ELECTRA). BMJ 2004; 328:144 147 22 Boudreaux ED, Clark S, Camargo CA Jr. Telephone follow-up after the emergency department visit: experience with acute asthma; on behalf of the MARC Investigators. Ann Emerg Med 2000; 35:555 563 23 Yoon R, McKenzie DK, Bauman A, et al. Controlled trial evaluation of an asthma education programme for adults. Thorax 1993; 48:1110 1116 24 Mulloy E, Donaghy D, Quigley C, et al. A one-year prospective audit of an asthma education programme in an outpatient setting. Ir Med J 1996; 89:226 228 25 Sharples LD, Edmunds J, Bilton D, et al. A randomised controlled crossover trial of nurse practitioner versus doctor led outpatient care in a bronchiectasis clinic. Thorax 2002; 57:661 666 www.chestjournal.org CHEST / 130 / 1/ JULY, 2006 57