Stability of asthma control with regular treatment: an analysis of the Gaining Optimal Asthma controL (GOAL) study.

BACKGROUND: Uncontrolled asthma is characterized by variability. Current asthma guidelines recommend focussing on the achievement and maintenance of control but few studies have examined in detail, using composite measures of control, the stability and potential duration of control once achieved. In this post-hoc analysis of the results of the Gaining Optimal Asthma controL (GOAL) study, we examine the association between the level of asthma control achieved during the step-up phase of the study and the stability of control experienced during the maintenance phase. METHODS: GOAL was a 1-year, randomized, stratified, double-blind study of 3421 patients with uncontrolled asthma, which compared salmeterol/fluticasone propionate combination with fluticasone propionate in achieving two composite, guideline-based measures of control: totally controlled and well-controlled asthma. We analysed the proportion and duration of time spent in control, the effect of treatment on asthma stability, and the impact of asthma control stability on unscheduled use of healthcare resources. RESULTS: In patients achieving well-controlled or totally controlled asthma, at least well-controlled asthma was maintained for a median of almost 3 and 6 months, and for more than 85% and 95% of weeks of follow-up, respectively. A high level of stability was confirmed in a Markov analysis investigating transitional probability of change in control status. Variability in control was associated with increased probability of an unscheduled healthcare resource use (odds ratio: 1.06, P < 0.001). CONCLUSIONS: Most patients achieving guideline-defined control can maintain at least a similar level of control with regular, stable dosing, with little likelihood of losing control.

GINA guidelines on asthma and beyond.

Clinical guidelines are systematically developed statements designed to help practitioners and patients make decisions regarding the appropriate health care for specific circumstances. Guidelines are based on the scientific evidence on therapeutic interventions. The first asthma guidelines were published in the mid 1980s when asthma became a recognized public health problem in many countries. The Global Initiative on Asthma (GINA) was launched in 1995 as a collaborative effort between the NHLBI and the World Health Organization (WHO). The first edition was opinion-based but updates were evidence-based. A new update of the GINA guidelines was recently available and it is based on the control of the disease. Asthma guidelines are prepared to stimulate the implementation of practical guidelines in order to reduce the global burden of asthma. Although asthma guidelines may not be perfect, they appear to be the best vehicle available to assist primary care physicians and patients to receive the best possible care of asthma.

The correlation between asthma control and health status: the GOAL study.

The present study examined the association between guideline-derived asthma control and health-related quality of life, assessed using the Asthma Quality of Life Questionnaire (AQLQ), in patients with uncontrolled asthma whose treatment was directed towards achieving the highest possible level of control. The present randomised, double-blind, parallel-group study compared the efficacy of fluticasone propionate (FP) and salmeterol/fluticasone propionate combination (SFC) in achieving two composite, guideline-derived measures of control: total control (TC) and well-controlled (WC) asthma. Not achieving these levels was classed as not well-controlled (NWC). Doses were augmented until patients achieved TC or reached the maximum dose. This dose was maintained for the remainder of the study. AQLQ was assessed at baseline and at each clinic visit. AQLQ scores improved throughout the study, reaching near-maximal levels in patients achieving TC and WC, and 52-week mean scores in the three control groups were statistically significantly different. Clinically meaningful improvements (mean change from baseline) were: TC group (SFC 1.9, FP 1.8), WC (SFC 1.5, FP 1.5) and NWC (SFC 1.0, FP 0.9). In conclusion, the treatment aimed at controlling asthma improves the health-related quality of life to levels approaching normal. The difference in Asthma Quality of Life Questionnaire scores between total control and well-controlled confirms that patients distinguish even between these high levels of control.

Cost-effectiveness of asthma control: an economic appraisal of the GOAL study.

BACKGROUND: The Gaining Optimal Asthma ControL (GOAL) study has shown the superiority of a combination of salmeterol/fluticasone propionate (SFC) compared with fluticasone propionate alone (FP) in terms of improving guideline defined asthma control. METHODS: Clinical and economic data were taken from the GOAL study, supplemented with data on health related quality of life, in order to estimate the cost per quality adjusted life year (QALY) results for each of three strata (previously corticosteroid-free, low- and moderate-dose corticosteroid users). A series of statistical models of trial outcomes was used to construct cost effectiveness estimates across the strata of the multinational GOAL study including adjustment to the UK experience. Uncertainty was handled using the non-parametric bootstrap. Cost-effectiveness was compared with other treatments for chronic conditions. RESULT: Salmeterol/fluticasone propionate improved the proportion of patients achieving totally and well-controlled weeks resulting in a similar QALY gain across the three strata of GOAL. Additional costs of treatment were greatest in stratum 1 and least in stratum 3, with some of the costs offset by reduced health care resource use. Cost-effectiveness by stratum was 7600 pound (95% CI: 4800-10,700 pound) per QALY gained for stratum 3; 11,000 pound (8600-14,600 pound) per QALY gained for stratum 2; and 13,700 pound (11,000-18,300 pound) per QALY gained for stratum 1. CONCLUSION: The GOAL study previously demonstrated the improvement in total control associated with the use of SFC compared with FP alone. This study suggests that this improvement in control is associated with cost-per-QALY figures that compare favourably with other uses of scarce health care resources.