Comparison of four-times-a-day and twice-a-day dosing regimens in subjects requiring 1200 micrograms or less of budesonide to control mild to moderate asthma

The aim of this study was to compare the efficacy, compliance and side-effects of budesonide administered twice daily (b.d.) and four times a day (q.d.) with a Turbuhaler device in asthmatic subjects requiring < or = 1200 micrograms daily. The randomized, parallel group study design included a 2-week baseline period followed by a 6-12-month treatment period. Subjects were assessed at regular intervals in hospital through FEV1, PC20 methacholine, adrenal function and throat swabs. They were asked to record their symptoms and PEF values morning and evening at home. An asthmatic flare-up, which was the main outcome resulting in a patient's termination of the study, was defined beforehand as (a) 25% or greater diurnal variability in PEF for 2 consecutive days, and/or (b) nocturnal awakenings due to asthma symptoms 2 days or more in the same week and/or (c) an increase (doubling or more) in the need for inhaled bronchodilator 2 days in the same week. Fifty-eight adult asthmatic subjects (20 males and 38 females) entered the study, one-half being randomly assigned to the b.d. regimen and one half to the q.d. regimen. Fourteen subjects were on 400 micrograms, 15 subjects on 800 micrograms and 29 subjects on 1200 micrograms of budesonide daily. Seventeen flare-ups were recorded in the b.d. regimen group as opposed to 11 in the q.d. regimen (P = 0.05), significant differences being found in the 800 and 1200 micrograms groups (a total of 13 flare-ups in the b.d. group and eight flare-ups in the q.d. group for the two doses, P = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Occupational asthma caused by dry metabisulphite

A case is described of occupational asthma in a worker with no previous history of asthma who sprinkled dried metabisulphite powder onto potatoes and developed work-related symptoms. Occupational asthma was confirmed by specific inhalation challenges.

Occupational asthma due to formaldehyde resin dust with and without reaction to formaldehyde gas

We report the cases of three subjects who developed asthma after being exposed to formaldehyde dust or gas. For two subjects, specific bronchial provocation tests with formaldehyde gas did not cause significant bronchoconstriction, whereas exposure to formaldehyde resin dust did. One subject experienced asthmatic reaction after being exposed to formaldehyde resin dust and gas. These findings suggest that the physical and chemical properties of formaldehyde are relevant to its likelihood of causing asthma.

The reversibility of airway obstruction to an inhaled beta 2-adrenergic agent is less satisfactory after methacholine testing in asthmatic subjects

AIMS

The aim of this work was to compare the response to an inhaled beta 2-adrenergic agent in two situations: (1) spontaneous airway obstruction in asthmatic subjects who had withheld treatment with the medication for more than 12 hs; and (2) after methacholine-induced airway obstruction once airway caliber had recovered to the premethacholine test value.

SUBJECTS AND METHODS

Sixteen asthmatic subjects who showed a 20% or more improvement in FEV1 after inhaled beta 2-adrenergic agent (B2) (salbutamol, 200 micrograms) entered a double-blind crossover randomized trial in which the following tests were carried out: (1) FEV1 response after inhaling a placebo or active B2; (2) FEV1 response after inhaling a placebo or active B2 after a methacholine test that had induced a 20% or more reduction in FEV1, once FEV1 had recovered to the premethacholine value after inhaling salbutamol in an open fashion.

RESULTS

As expected, the mean percent improvement in FEV1 in the spontaneous airway obstruction situation was 21.7 +/- 8.5% after inhaling the active B2 and 2.2 +/- 1.8% after placebo B2 (p < 0.001). Following recovery after methacholine challenge, the FEV1 was slightly superior (mean difference of 146 mL) to the premethacholine value before inhaling the active or placebo B2. In this situation, the percent improvement in FEV1 after inhaling the active B2 was only 7.5 +/- 4.4% and not significantly different from after inhaling placebo B2 (4.9 +/- 5.4%). Consequently, the end FEV1 value after inhaling active B2 was significantly higher in a situation of spontaneous airway obstruction than after methacholine-induced airway obstruction (mean difference = 110 mL; p = 0.02).

CONCLUSION

After a methacholine test, the reversibility of an inhaled beta 2 agent is not significantly different from a placebo and is less satisfactory than in a situation of spontaneous airway obstruction. The mechanism for this needs to be explored but it is not secondary to persisting airway obstruction.

Occupational asthma due to formaldehyde resin dust with and without reaction to formaldehyde gas

We report the cases of three subjects who developed asthma after being exposed to formaldehyde dust or gas. For two subjects, specific bronchial provocation tests with formaldehyde gas did not cause significant bronchoconstriction, whereas exposure to formaldehyde resin dust did. One subject experienced asthmatic reaction after being exposed to formaldehyde resin dust and gas. These findings suggest that the physical and chemical properties of formaldehyde are relevant to its likelihood of causing asthma.

Aluminium potroom asthma confirmed by monitoring of forced expiratory volume in one second

Chronic airflow obstruction has long been seen among aluminium potroom workers. Currently referred to as "potroom asthma," it is debatable as to whether it is occupational asthma or nonspecific airway obstruction. A 35-yr-old male lifelong nonsmoker, with no history of asthma or atopy, was hired by an aluminium plant that had begun its operation in 1986. Preemployment screening, consisting of spirometry and a chest radiograph, was normal. During his 12-h shifts, he replaced 10 to 20 anodes (prebake type), spending 5 min each time close to open pots releasing hot fumes. The patient experienced episodes of cough and dyspnea, which were resolved during withdrawal from work in January and December 1991. He resumed work in the potrooms in March 1992, his dyspnea recurred at work and at night with 25% drops in peak expiratory flow rates (PEFR), associated with mild-to-moderate bronchial hyperresponsiveness (PC20 histamine, 1.0 mg/ml). After a chest physician's assessment, he was withdrawn from the potroom department. Assessment of the bronchial response to the occupational exposure in potrooms carried out in November 1992 revealed a pattern of dual asthmatic response, paralleled by a drop in PC20 methacholine from 5.1 to 0.7 mg/ml. A similar pattern was seen again during repeat workplace challenges 3 wk later. Spirometry obtained on control days was stable. We conclude that asthmatic reactions can exist among workers in aluminium smelters.

Prevalence of occupational asthma among workers exposed to eastern white cedar

We assessed the prevalence of occupational asthma among current (n = 29/31, 94%) and former (n = 13/49, 27%) employees of a sawmill in which eastern white cedar has been made into shingles during the past 3 yr. All participants answered a respiratory questionnaire, and all except one underwent spirometry and methacholine inhalation tests. All those with bronchial hyperresponsiveness (PC20 methacholine < or = 19 mg/ml) were invited to undergo specific inhalation challenges. Mean duration of exposure was 13 mo (19 workers > 12 mo). Twenty-eight workers (65%) reported a history compatible with asthma, and 25 (58%) had symptoms that were suggestive of occupational asthma. Only two subjects had significant airway obstruction (FEV1 < 80% pred) (mean value = 98% pred). Eighteen subjects (42%) had a PC20 < or = 16 mg/ml. Specific inhalation tests with plicatic acid and/or western red cedar (which contains twice as much plicatic acid as eastern white cedar), were done on 12 subjects who had a PC20 < or = 16 mg/ml when they were assessed. Three subjects were considered to have positive tests (one had an isolated immediate reaction, one had a late reaction, and one had significant changes in PC20 each time he was exposed but no changes in FEV1). Environmental monitoring showed concentrations of total dusts above 2 mg/m3 in half of the samples. The prevalence of occupational asthma in this workplace was three of 42 participants (7%) or at least three of 80 (3.8%) of all current or ex-workers. This is comparable to the prevalence of occupational asthma in subjects exposed to western red cedar.

Comparison between peak expiratory flow rates (PEFR) and FEV1 in the monitoring of asthmatic subjects at an outpatient clinic

Peak expiratory flow rate (PEFR) monitoring is often used alone in evaluating bronchial caliber and the response to a bronchodilator in the assessment of asthmatic subjects. A 15% change in airway caliber has been proposed as the criteria for modifying treatment. Our aim was to determine if changes in PEFR from one visit to the next can adequately evaluate changes in airway caliber as assessed by FEV1, which is considered the gold standard, and to identify the characteristics of subjects whose evaluations were inadequate. This was a retrospective study of 197 asthmatic subjects seen regularly at an outpatient clinic for whom FEV1 and PEFR assessments, prebronchodilator and postbronchodilator, were available for two visits. There was a high correlation between PEFR and FEV1 (in absolute value or percent predicted) (r = 0.83 and r = 0.75). However, 24 of 56 (43%) of those who had a change in FEV1 of 15% or more between two visits (mean change [%] +/- SD, range [best-lowest/best] = 20.9 +/- 5.1%, 15 to 36%) showed changes in PEFR of less than 15% (6.7 +/- 6.5%, 8.0 to 13.9%). On the other hand, 14 of 42 (33%) subjects with changes in FEV1 of less than 15% (9.8 +/- 3.2%, 1.1 to 13.8%) had changes in PEFR of 15% or more (22.2 +/- 10.9%, 16 to 35%). This discrepancy was not related to differences in baseline FEV1, control status, or the relationship between changes in FEV1 and PEFR in response to a bronchodilator. In conclusion, assessment of airway caliber through PEFR monitoring may not be valid in some asthmatic subjects and can often lead to underestimation or overestimation of changes in FEV1. None of the explanations considered made it possible to identify these subjects.

Bronchial hyperresponsiveness can improve while spirometry plateaus two to three years after repeated exposure to chlorine causing respiratory symptoms

Repeated exposure to chlorine in pulp mills and paper can induce persistent asthma-like symptoms such as bronchial hyperresponsiveness and variable changes in airway caliber. The long-term time course of bronchial hyperresponsiveness has not been examined. We studied 20 of 29 subjects (69% participation rate) who demonstrated bronchial hyperresponsiveness to methacholine when they were first assessed, 18 to 24 mo after repeatedly inhaling "puffs" of high concentrations of chlorine in a paper mill over a 3-mo period. Each subject answered a respiratory questionnaire and underwent spirometry and a methacholine inhalation test 12 mo after the initial survey, 30 to 36 mo after the chlorine inhalations. Three subjects required inhaled steroids at the time of the initial survey and three at the time of the second, including two who carried on using these preparations. Only one subject changed smoking habits. There were no significant overall changes in FEV1 on the two occasions, nine subjects having a FEV1 < 80% on the first occasion and eight on the second. Six of the 18 subjects (33%) who underwent a methacholine inhalation test on both occasions had significantly improved PC20 results, including five for whom the PC20 value was within the normal range. All six subjects had normal FEV1 values on both assessments. Although changes in spirometry induced by repeated exposure to chlorine seem to persist, bronchial hyperresponsiveness can improve significantly in those with normal airway caliber. This suggests that less pronounced bronchial alterations induced by repeated exposures to chlorine may be reversible.

Airway inflammation after removal from the causal agent in occupational asthma due to high and low molecular weight agents

In order to determine 1) the features of airway inflammation after removal from exposure to high (HMW) and low (LMW) molecular weight agents 2) if there are any differences in the pattern of inflammation induced by these two types of agents, we studied 18 subjects with a recently confirmed diagnosis of occupational asthma (OA) due to HMW (n = 11) and LMW (n = 7) agents. The duration of asthma symptoms varied from 2 to 108 months (mean 33 months), and withdrawal from exposure to the sensitizing agent from 3 to 24 weeks (mean 10 weeks). All subjects underwent measurements of expiratory flow rates, methacholine inhalation tests, and a flexible bronchoscopy with bronchoalveolar lavage (BAL) and bronchial biopsies. Endoscopic findings were compared with a group of 10 normal subjects. At the time of the bronchoscopy, asthma symptoms were minimal in most subjects. Although 15/18 subjects had normal forced expiratory volume in one second (FEV1 > 80% pred), all subjects had increased airway responsiveness to methacholine (provocation concentration producing a 20% fall in FEV1 = 0.2-10.0 mg.ml-1). BAL analysis showed similar median percentages of the total number of cells and differentials in control subjects and those exposed to HMW and LMW agents. Bronchial biopsies showed that mean inflammatory cell count, both epithelial and sub-epithelial, was similarly raised in OA subjects exposed to either HMW or LMW agents, compared to controls, except for epithelial lymphocyte count. In contrast to the controls, bronchial biopsy of both groups with OA also showed other changes such as extensive epithelial desquamation, ciliary abnormalities of the epithelial cells, smooth muscle hyperplasia and subepithelial fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of circadian variations using FEV1 and peak expiratory flow rates among normal and asthmatic subjects

BACKGROUND

Most studies that describe circadian variations in asthma have used maximum rate of peak expiratory flow (PEF) rather than forced expiratory volume in one second (FEV1) to assess airway calibre. This study was designed to assess circadian variations in PEF and FEV1 measured simultaneously and to compare variations in these measurements in normal and asthmatic subjects in a stable clinical state.

METHODS

Twenty nine subjects (nine asthmatic subjects on bronchodilators, 10 on inhaled steroids, and 10 normal controls) were asked to record their PEF and FEV1 with a new portable instrument every two hours during the day and once on waking at night for two weeks. Circadian variations were examined in different ways using arithmetical indices and cosinor analysis.

RESULTS

78% of PEF values and 75% of FEV1 values were considered to be reproducible and were included in the analysis. Variations obtained using PEF did not differ from those obtained using FEV1. Significant cosinor variations were found in at least 50% of recording days for most of the subjects and showed the same features as for arithmetical indices. Daily variations in PEF and FEV1 were significantly correlated with airway calibre and PC20 methacholine (r approximately 0.5 to approximately 0.6).

CONCLUSIONS

PEF is as satisfactory as FEV1 for describing circadian variations among normal subjects and stable asthmatic subjects.

Medicolegal and compensation aspects of occupational asthma

The medicolegal aspects (primary prevention, secondary prevention or surveillance) and the system of compensation (tertiary prevention) for occupational asthma are reviewed in this article. Due to the significant medical, medicolegal, social and financial consequences, it is of the utmost importance that the diagnosis of occupational asthma be proved by objective means, whenever feasible. Compensation for temporary and permanent disability/impairment should be offered to workers. Attempts to retain subjects rapidly and efficiently are preferable, as occupational asthma generally affects young workers. The evaluation of permanent asthma and the awarding of relative permanent disability compensation should be effected 2 yrs after exposure to the causative agent has ended, as asthma generally persists even after exposure to the causative agent ceases. A tabulated review of prevailing medicolegal compensation systems in various countries is presented. Data on an evaluative assessment of the Quebec system of compensation are included.

Medicolegal and compensation aspects of occupational asthma

The medicolegal aspects (primary prevention, secondary prevention or surveillance) and the system of compensation (tertiary prevention) for occupational asthma are reviewed in this article. Due to the significant medical, medicolegal, social and financial consequences, it is of the utmost importance that the diagnosis of occupational asthma be proved by objective means, whenever feasible. Compensation for temporary and permanent disability/impairment should be offered to workers. Attempts to retain subjects rapidly and efficiently are preferable, as occupational asthma generally affects young workers. The evaluation of permanent asthma and the awarding of relative permanent disability compensation should be effected 2 yrs after exposure to the causative agent has ended, as asthma generally persists even after exposure to the causative agent ceases. A tabulated review of prevailing medicolegal compensation systems in various countries is presented. Data on an evaluative assessment of the Quebec system of compensation are included.

Survey of construction workers repeatedly exposed to chlorine over a three to six month period in a pulpmill: II. Follow up of affected workers by questionnaire, spirometry, and assessment of bronchial responsiveness 18 to 24 months after exposure ended

OBJECTIVE

The aim was to determine the prevalence of persistent respiratory symptoms and bronchial hyper-responsiveness due to reactive airways dysfunction syndrome in a population of construction workers at moderate to high risk of developing the syndrome, at an interval of 18 to 24 months after multiple exposures to chlorine gas during renovations to a pulp and paper mill.

DESIGN AND PARTICIPANTS

71 of 289 exposed workers (25%) were identified on the basis of an exposure and the onset of respiratory symptoms shortly after this event (moderate to high risk). A standardised respiratory questionnaire was first presented, followed by spirometry and a methacholine inhalation test on those whose questionnaire suggested the persistence of respiratory symptoms.

RESULTS

64 of 71 (90%) subjects completed the respiratory questionnaire at the time of the follow up. The questionnaire suggested a persistence of respiratory symptoms in 58 of the 64 workers (91%). Of the 58 subjects, 51 underwent spirometry and assessment of bronchial responsiveness. All of them used bronchodilators as required (not regularly) and four required inhaled anti-inflammatory preparations. Sixteen had bronchial obstruction (forced expiratory volume in one second) (FEV1 < 80% predicted) and 29 showed significant bronchial hyper-responsiveness.

CONCLUSION

Of the subjects (n = 71) who were at moderate to high risk of developing reactive airways dysfunction syndrome after being exposed to chlorine and were seen 18 to 24 months after exposure ended, 58 (82%) still had respiratory symptoms, 16 (23%) had evidence of bronchial obstruction, and 29 (41%) had bronchial hyper-responsiveness.

Respiratory and systemic reaction following exposure to heated electrostatic polyester paint

A 39 year old nonatopic man developed episodes of cough, dyspnoea, sweating and shivers within 2-3 weeks of starting a new job in a factory where metallic boards were treated with an electrostatic powder paint, made of an epoxy resin and a carboxylated polyester containing polyethylene terephthalate and polybutylene terephthalate. The subject sprayed the metallic boards which were then heated in 200 degrees C ovens. The subject was first seen in an emergency room after being at work for 4 h. The physical examination revealed bilateral wheezing with fever (39 degrees C), hypoxaemia (arterial oxygen tension (PaO2) 58 torr (7.7 kPa), leucocytosis (white blood count cells.mm-3 17,000 (17 x 10(9) cells.l-1) and severe airway obstruction (forced expiratory volume in one second (FEV1)/forced vital capacity, (FVC) 1.3/2.4 l, improving to 2.2/3.8 l after bronchodilator; predicted values = 3.4/4.1 l). The subjects condition improved after being treated with oral steroids. His spirometry was normal two weeks later, although he showed mild bronchial hyperresponsiveness to methacholine with the (provocative concentration producing a 20% fall in FEV1 (PC20) being 1.7 mg.ml-1). The subject underwent specific inhalation challenges at the workplace 4 months later. After being exposed at work for 4 h, he developed a significant fall in FEV1 (-40%), fever, leucocytosis, and a fall in diffusing capacity. Lung function tests were back to normal two weeks later. Exposing the subject to heated granulated polyester for one hour in a hospital laboratory produced a fall in FEV1 of 41%, fever, leucocytosis and a fall in diffusing capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Occupational asthma due to heated polypropylene

A 35 year-old nonatopic woman was referred to the hospital for possible work-related asthma. She had worked as an operator, at a plant producing polypropylene bags, for the previous four yrs. Her main complaint was a productive cough with dyspnoea and wheezing, as well as rhinitis over the past 3 yrs. She had been absent from work for 6 months on maternity leave, and had improved greatly. She was on a beta 2-adrenergic agent and had to take it at least four times daily. Baseline spirometry whilst at work showed marked airflow obstruction (forced expiratory volume in one second (FEV1) of 43% predicted (pred). After two months away from work FEV1 improved to 89% pred; provocative concentration of histamine causing a 25% fall in FEV1 (PC20) was 3.6 mg.ml-1 (mild airway hyperresponsiveness). Return to work resulted in a marked deterioration in FEV1, and serial peak expiratory flow (PEFR) values. PC20 was 0.11 mg.ml-1 (severe airway hyperresponsiveness) one week after she had returned to work. Specific inhalation challenges with polypropylene heated to 250 degrees C resulted in a late asthmatic reaction. As formaldehyde is one of the degradation products of heating polypropylene, we exposed her to it for up to 2 h, but we elicited no bronchospastic reaction. We conclude that heated polypropylene should be listed as one of the agents that causes occupational asthma.

Occupational asthma due to heated polypropylene

A 35 year-old nonatopic woman was referred to the hospital for possible work-related asthma. She had worked as an operator, at a plant producing polypropylene bags, for the previous four yrs. Her main complaint was a productive cough with dyspnoea and wheezing, as well as rhinitis over the past 3 yrs. She had been absent from work for 6 months on maternity leave, and had improved greatly. She was on a beta 2-adrenergic agent and had to take it at least four times daily. Baseline spirometry whilst at work showed marked airflow obstruction (forced expiratory volume in one second (FEV1) of 43% predicted (pred). After two months away from work FEV1 improved to 89% pred; provocative concentration of histamine causing a 25% fall in FEV1 (PC20) was 3.6 mg.ml-1 (mild airway hyperresponsiveness). Return to work resulted in a marked deterioration in FEV1, and serial peak expiratory flow (PEFR) values. PC20 was 0.11 mg.ml-1 (severe airway hyperresponsiveness) one week after she had returned to work. Specific inhalation challenges with polypropylene heated to 250 degrees C resulted in a late asthmatic reaction. As formaldehyde is one of the degradation products of heating polypropylene, we exposed her to it for up to 2 h, but we elicited no bronchospastic reaction. We conclude that heated polypropylene should be listed as one of the agents that causes occupational asthma.

Aetiological agents in occupational asthma

Occupational asthma has become the most prevalent occupational lung disease in developed countries. At present, about 200 agents have been implicated in causing occupational asthma in the workplace. These agents can be divided into two categories by their mechanism of action: immunological and nonimmunological. Immunological causes can be further divided into those that induce asthma through an immunoglobulin E (IgE)-dependent mechanism, and those that induce asthma through a non-IgE-dependent mechanism. In the latter category, specific IgE antibodies are found only in a small percentage of the patients with proven disease, even though the clinical picture is compatible with an allergic reaction. The immunological mechanism(s) responsible for these agents has yet to be identified. The best known example of nonimmunological asthma is Reactive Airways Dysfunction Syndrome (RADS) or irritant-induced asthma. In this review, examples of types of agents causing occupational asthma are discussed and a compendium table of aetiological agents is given.

Is reactive airways dysfunction syndrome a variant of occupational asthma?

BACKGROUND

Reactive airways dysfunction syndrome (RADS) or irritant-induced asthma is a syndrome that leaves subjects with asthma-like symptoms after one or more exposures to a high concentration of an irritant substance. The degree of reversibility of airway obstruction in subjects with RADS is nevertheless unknown, as is the degree of associated lesions at the airway level.

METHODS

We compared the acute reversibility of forced expiratory volume in 1 second (FEV1) after inhalation of albuterol (200 micrograms) in 15 subjects with RADS (12 cases caused by chlorine inhalation) with that of 30 subjects with occupational asthma (OA) caused by various agents. They were paired according to baseline airway obstruction (61% and 63% of predicted value in the RADS and OA groups), requirement for medication (bronchodilator only--7 of 15 subjects with RADS and 14 of 30 subjects with OA--as compared with bronchodilator + inhaled steroids in 8 of 15 subjects with RADS and 16 of 30 subjects with OA, respectively), and interval since removal from exposure (means of 30 and 24 months in the RADS and OA groups). In addition, five nonsmokers with RADS who had not received inhaled steroids underwent bronchoscopy with lavage and bronchial biopsies less than 2 years after the exposure.

RESULTS

The percentage increase in FEV1 over baseline after inhalation of albuterol was 10% +/- 9% in the RADS group and 19% +/- 16% in the OA group (p = 0.005). Only 2 of 15 subjects (13%) with RADS and 12 of 30 subjects (40%) with OA showed an improvement in FEV1 of 20% or greater after inhalation of albuterol. Bronchoalveolar lavage showed an increased number of cells with a predominance of lymphocytes, and biopsy specimens showed increased basement membrane thickness in the five subjects with RADS who underwent bronchoscopy.

CONCLUSION

Subjects with RADS are generally left with less airway reversibility than those with OA. We suggest that this difference is secondary to distinct pathologic changes.

How many times per day should peak expiratory flow rates be assessed when investigating occupational asthma?

BACKGROUND

Serial peak expiratory flow rate (PEF) recording has been advocated as a sensitive and specific means of confirming work related asthma. The optimum number of recordings per day to achieve the best between-reader and within-reader reproducibility and sensitivity/specificity ratio compared with the final diagnosis determined by specific inhalation challenges is unknown.

METHODS

PEF recording was carried out every two hours in 74 subjects referred for possible occupational asthma. Specific inhalation challenges performed in a hospital laboratory or at the workplace (positive in 33 subjects and negative in 41) were considered the gold standard. The duration of monitoring at work and away from work was at least two weeks each. Graphs of PEF recordings were generated in four different ways: every two hours, four times/day, three times/day, and every morning and evening. The graphs were assessed by three readers in three different centres in a blind manner. Furthermore, one third of each type of graph was read blind by the same reader one week after the initial interpretation.

RESULTS

Agreement between the three readers was a little more frequent (82%) in the case of the every two hour readings than for the other types of readings (70% v 77%). Agreement between at least two of the three readers occurred in 73% of positive challenges (sensitivity) and in 78% of negative challenges (specificity) for every two hour readings. The figures varied from 61% to 70% for positive challenges and from 78% to 88% for negative challenges for the other types of readings. Within-subject reproducibility from one reading to the next (one week apart) was excellent (83% to 100%).

CONCLUSIONS

Recording PEF every two hours results in a slightly more satisfactory agreement between readers and in concordance in terms of sensitivity/specificity than less frequent PEF readings, although the four times a day assessment is almost as satisfactory.

A dose-ranging study of fluticasone propionate in adult patients with moderate asthma. International Study Group

In this 4-week, multicenter, double-blind, randomized, parallel group study, the dose-effect relationship of four doses of inhaled fluticasone propionate (50, 100, 200, and 400 micrograms twice daily) was investigated and compared with beclomethasone dipropionate, 200 micrograms twice daily. A total of 672 patients with moderate asthma currently receiving 1,000 micrograms/d or less of an inhaled steroid were recruited. The study demonstrated a significant dose-related improvement in lung function with fluticasone propionate. Linear dose-related increases were observed in morning (increase per doubling dose was 4.3 L/min; 95 percent confidence interval [CI], 1.8, 6.8 L/min; p = 0.001) and evening peak expiratory flow rate (PEFR) (increase per doubling dose was 3.0 L/min; 95 percent CI, 0.5, 5.5 L/min; p = 0.017), clinic lung function (at 4 weeks, increase in percent predicted PEFR per doubling dose = 1.1 percent; 95 percent CI, 0.2, 2.1 percent; p = 0.022; increase in percent predicted FEV1 per doubling dose = 1.1 percent; 95 percent CI, 0.3, 1.9 percent; p = 0.10:increase in percent predicted FVC per doubling dose = 1.3 percent, 95 percent CI, 0.5, 2.1 percent; p = 0.001), and the percentage of symptom-free days over days 1 to 14 of treatment (increase per doubling dose = 1.9, 95 percent CI, 0.0, 3.9; p = 0.048). There was also a dose-related reduction in extra bronchodilator usage (days 1 to 14 p = 0.002; days 15 to 28 p = 0.01). In addition, there was a significant decrease in diurnal variation with increasing doses of fluticasone propionate (decrease per doubling dose = 2.0 L/min, 95 percent CI, 0.4; p = 0.024). The number of asthma exacerbations was also reduced as the dose of fluticasone propionate increased. Fluticasone propionate was well tolerated, adverse events were few, and there was a similar incidence in all groups. Furthermore, there was no evidence of any hypothalamic pituitary adrenal axis suppression. The data from the study were consistent with other clinical studies that have shown fluticasone propionate to be more potent than beclomethasone dipropionate in terms of improvement in lung function. In conclusion, this study provided evidence of a dose-related improvement in asthma control for fluticasone propionate in the dose range 100 to 800 micrograms daily, in patients with moderate asthma.