Dec 16 2016
With headlines questioning whether science is broken, the skyrocketing costs of drug development, the high rates of obesity, and the recent decrease (though by only 0.1 years!) in life expectancy in the US, it can be tough to be an optimist in biomedical research – gloom and doom lurk just about everywhere. This is doubly so for someone like myself who is both an innate and a trained pessimist, what with my training in Biostatistics. However, I have been coming across numerous examples of successes in biomedical research and public health implementation from the past 60 years, and therefore want to share them in a multipart series here – my first foray into blogging – in order to spread cheer and hope in time for the holidays.
Research is hard and the only problems we tackle are those for which no solutions have yet been found. There are reasons why no longer look for cures for smallpox and polio! The prevention of many infectious diseases is well recognized as a huge public health success. I want to shed a bit more light on quieter success stories – There are many other examples which, though not as dramatic, show that science works and for many lesser known diseases that nonetheless affect many people in total, there is less suffering and more hope. I will be focusing on US examples, because these are the ones I am most familiar with, and welcome other examples in the comments.
Newborn screening programs for congenital diseases are valuable public health interventions, currently implemented in every state in the US – though the exact diseases considered are different in each state – and many other countries around the world via a blood test performed shortly after birth. In case of a positive result for one of the screened diseases, follow-up testing is performed to confirm the presence of the disease. The “poster diseases” for screening are phenylketonuria (PKU) – a recessive disease affecting 1 in 13,000 births – and congenital hypothyroidism (CH) – affecting 1 in 4000 births – for which screening has existed since the 1960s, respectively 1970s. In the absence of management, they both generally result in severe intellectual disabilities along with other potential health issues. The impact of these diseases can now be functionally eliminated via, respectively, a restricted diet, and a hormone supplement, both of which must be started shortly after birth. To give an idea of the human cost, consider the writer Pearl Buck, a novelist who won the Pulitzer prize in 1932 and became the first American woman to win the Nobel Prize for Literature in 1938. Her daughter Carol, born in 1920, had PKU and was institutionalized for most of her life. Part of the reason why she wrote her famous novel “The Good Earth” was to help pay for her daughter’s care. She would also write to her friend Polly Small “I would gladly have written nothing if I could have just an average child in Carol. Average children seem such a wonderful joy to me – I wouldn’t ask for a clever, bright child if I could have had her just average.” Buck would later publish the book “The Child Who Never Grew” in 1950, which is considered one of the first books to openly discuss intellectual disability.
Newborn screening panels are actively evolving, with a Recommended Uniform Screening Panel developed by the Secretary’s Advisory Committee on Heritable Disorders in Newborns and Children (SACHDNC) of the Department of Health and Human Services currently encompassing 34 core conditions. In general, diseases are included only if a treatment or management plan is expected to substantially alter the disease course if started before symptoms appear – this can be a difficult evidence-based medicine question and as such there is not always complete agreement. Other biomedical and ethical concerns – also see here and here – including issues such as:
- Does the screening test have good performance in terms of false positives and false negatives? What are the costs of a false positive?
- Should screening be performed for diseases without treatment or for carrier status so that families could be informed of risk to future pregnancies or be prepared for caring for a special-needs child?
While more work needs to be done in this area (I wouldn’t be a researcher if I didn’t end on this note), it is important to keep in mind that many children are already being substantially helped by this screening. In 2014, 3,988,076 babies were born in the US, which means that approximately 1,300 lives were fundamentally transformed by CH and PKU screening alone.