Age, Income Linked to Ventilation Use of ALS Patients in Korea
Age, socioeconomic status, and co-existing conditions are among the factors that can lead to a need for assisted ventilation in people with amyotrophic lateral sclerosis (ALS), research from Korea reports.
Since ALS affects the diaphragm muscles and a person’s breathing ability, many with ALS will need assisted ventilation — the process of using a machine to support breathing — at some point in the course of their disease. It can be either invasive, and given via a tracheostomy or a surgical incision of the windpipe, or non-invasive.
Non-invasive ventilation is the treatment of choice for breathing difficulties in ALS patients. Guidelines from the American Academy of Neurology recommend that patients start using this form of ventilation when their forced vital capacity — the amount of air they can forcibly exhale during a lung test — falls below 50% of the predicted value.
However, previous studies have found that only 36% of patients who reach that threshold of lung function are using assisted ventilation, the researchers noted.
A number of factors, such as sex, age, marital status, and disease severity are thought to affect the use of non-invasive ventilation, but most studies involved patients in Western countries.
A team of researchers in Korea sought to investigate the overall use of assisted ventilation and factors linked to its use among ALS patients in that country Koreans with ALS.
“Ethnic differences in ALS regarding genetic variation between the European and Korean populations have been reported, which could lead to different processes of disease progression and management strategies,” the researchers wrote. They included socioeconomic status due to the costs of managing ALS in aging populations.
A rare disease, nationwide registry data search identified 3,057 people diagnosed with ALS in Korea between 2011 and 2017, and followed for about six years. Among them, 1,228 (40%) started using assisted ventilation during the follow-up period, with 956 (31.3%) using non-invasive ventilation, and 272 (8.9%) needing tracheostomy invasive ventilation.
Overall, no relationship was found between sex and use of assisted ventilation. However, statistical analyses demonstrated that a gastrostomy (a tube placed into the stomach for nutritional support), pneumonia, a greater number of co-existing conditions (comorbidities), a higher income, and use of specialized-care (tertiary) hospitals were all independently associated with an increased likelihood of a patient using ventilatory support.
In contrast, patients who were 70 or older, lived in non-metropolitan areas, and had what is called “medical aid” insurance — possibly as opposed to national health insurance — were less likely to use assisted ventilation.
People ages 60 to 69 were the largest group by age on assisted ventilation (34.9% of 1,228, or 428 patients) followed by those in their 50s (28.7% or 352 patients).
Researchers speculated that the lower relative use of assisted ventilation in more elderly patients may be “due to low life expectancy in real-world practice,” they wrote.
When studying data according to the type of assisted ventilation used, higher income earners and users of tertiary hospitals were found to be more likely to use non-invasive ventilation, which again particularly dropped among those 70 or older. No association was found between these factors and the use of tracheostomy invasive ventilation.
Patients needing a nasogastric tube — which carries food and medicine to the stomach through the nose — were more likely to use tracheostomy invasive ventilation than non-invasive ventilation, given that the “masks or nasal prongs for NIV [non-invasive ventilation] might be intolerable” for these people.
Of note, a significant association between lesser use of assisted ventilation and living in non-metropolitan areas was only observed in women, while an association between higher income and use of ventilatory support was only seen in men.
A study limitation, the researchers noted, was reliance on data that lacked respiratory symptoms, disease severity, and ALS subtype, as well as the results of pulmonary function tests.
“We found that various factors, including age, socioeconomic status, and medical condition, were related with assisted ventilation use,” the researchers wrote. “Understanding the pattern of assisted ventilation use would help set optimal management strategies in patients with ALS.”