Division of Therapeutics and Molecular Medicine and Respiratory Biomedical Research Unit, University of Nottingham, Nottingham, UK.
QJM. 2011 Nov;104(11):971-9. doi: 10.1093/qjmed/hcr116. Epub 2011 Jul 15.
Understanding the true prevalence of lymphangioleiomyomatosis (LAM) is important in estimating disease burden and targeting specific interventions. As with all rare diseases, obtaining reliable epidemiological data is difficult and requires innovative approaches.
To determine the prevalence and incidence of LAM using data from patient organizations in seven countries, and to use the extent to which the prevalence of LAM varies regionally and nationally to determine whether prevalence estimates are related to health-care provision.
Numbers of women with LAM were obtained from patient groups and national databases from seven countries (n = 1001). Prevalence was calculated for regions within countries using female population figures from census data. Incidence estimates were calculated for the USA, UK and Switzerland. Regional variation in prevalence and changes in incidence over time were analysed using Poisson regression and linear regression.
Prevalence of LAM in the seven countries ranged from 3.4 to 7.8/million women with significant variation, both between countries and between states in the USA. This variation did not relate to the number of pulmonary specialists in the region nor the percentage of population with health insurance, but suggests a large number of patients remain undiagnosed. The incidence of LAM from 2004 to 2008 ranged from 0.23 to 0.31/million women/per year in the USA, UK and Switzerland.
Using this method, we have found that the prevalence of LAM is higher than that previously recorded and that many patients with LAM are undiagnosed.
了解淋巴管平滑肌瘤病（LAM）的真实患病率对于评估疾病负担和针对特定干预措施非常重要。与所有罕见病一样，获得可靠的流行病学数据具有挑战性，需要创新的方法。
使用来自七个国家的患者组织的数据来确定 LAM 的患病率和发病率，并利用 LAM 患病率在区域和国家之间的差异程度来确定患病率估计是否与医疗保健提供有关。
从七个国家的患者团体和国家数据库中获得患有 LAM 的女性人数（n=1001）。使用人口普查数据中的女性人口数字，计算各国各地区的患病率。计算了美国、英国和瑞士的发病率估计值。使用泊松回归和线性回归分析患病率的区域差异和随时间的发病率变化。
七个国家的 LAM 患病率范围为 3.4 至 7.8/百万女性，存在显著差异，包括国家之间和美国各州之间的差异。这种差异与该地区的肺科专家数量或人口中拥有医疗保险的百分比无关，但表明大量患者未被诊断。2004 年至 2008 年期间，美国、英国和瑞士的 LAM 发病率范围为 0.23 至 0.31/百万女性/年。
使用这种方法，我们发现 LAM 的患病率高于之前记录的患病率，并且许多 LAM 患者未被诊断。
