Drmichaelhanrahan (2026)

09/12/2025

Little Oscar arrived just a few weeks ago and like all new parents, we want to do everything we can to keep him safe and well through his first winter.

One thing that’s given us real peace of mind is knowing he is protected against RSV (respiratory syncytial virus), a common virus that can cause serious illness in young infants. It’s one less thing to worry about during these early months.

I was involved in evaluating the HSE’s RSV Immunisation Pathfinder Programme last year, and the evidence was compelling — we observed a 76% drop in babies requiring hospitalisation and a 65% drop in babies needing intensive care due to complications of RSV compared to the previous winter.

If you’re welcoming a baby this winter, I’d strongly encourage you to make sure they get the RSV immunisation for your child too. It's available for all newborn babies born during RSV season - from early September 2025 until the end of February 2026.

It’s also available for babies born between 1st March and 31st August until the end of this week (visit https://www2.hse.ie/conditions/rsv/immunisation/ for the latest details).

15/10/2025

Gambling is a recognised behavioural addiction that can seriously impact mental health, personal finances and relationships. It is important to emphasise that gambling does not resolve financial difficulties and may lead to further harm, especially when combined with alcohol. If you or someone you know is struggling, professional support is available, early intervention can prevent more severe consequences. Prioritise health: avoid gambling and seek help if needed.

14/10/2025

Many things can happen at the same time, but that doesn’t mean one is causing the other! For example, ice cream sales and sunburn rates both go up in summer, but eating ice cream doesn’t cause sunburn. Always look for the real cause before jumping to conclusions—correlation does not equal causation. This is a key concept in epidemiology and public health research!

12/10/2025

Melanoma cases in Ireland have risen steadily since the 1990s, according to data from the National Cancer Registry. This highlights the growing importance of sun protection, skin cancer awareness, and early detection. Remember, prevention and regular skin checks can save lives.

09/10/2025

Vitamin D is essential for strong bones, teeth, and a healthy immune system - yet half of us aren’t getting enough. It helps your body absorb calcium, prevents weak bones, lowers osteoporosis risk, and keeps inflammation in check. Get your vitamin D from sunlight, foods, or supplements for better health!

17/01/2025

Just published my latest research article in the Irish Journal of Medical Science. This study looked at all emergency department (ED) presentations for those categorised during triage as "apparently drunk" in the Mercy University Hospital in Cork for 2022 and 2023.

A total of 1662 presentations were categorised as “Apparently Drunk,” representing 3% of all ED visits. There was an 18% increase in such presentations from 2022 to 2023. The majority of patients were male (72%). The median age was 39 years. Notably, 23% of the presentations involved people experiencing homelessness, and 81% were conveyed by ambulance. Associated complaints included head injuries (7%), falls/collapses (6%), mental health issues (5%), and assaults (4%).

The findings indicate a growing trend in patients presenting to the ED as “Apparently Drunk”. The high incidence among people experiencing homelessness and the substantial resource utilisation underscores the need for targeted public health interventions and integrated services. Policymakers should consider these findings in the context of potential legislative changes that may impact alcohol availability.

30/07/2024

Cost-effectiveness analysis (CEA) is an economic evaluation method that compares the costs and health outcomes of different interventions. It quantifies how much it costs to achieve a specific health benefit, such as years of life gained or diseases prevented. By calculating the cost-effectiveness ratio, which is the net cost divided by the health outcome, CEA helps determine which intervention provides the best value for money relative to alternatives, including the status quo.

CEA is particularly useful in public health and policy decision-making, as it allows for informed resource allocation by highlighting the trade-offs between costs and health gains. This analysis can guide policymakers in selecting interventions that maximize health benefits within budget constraints, ultimately improving health outcomes while ensuring efficient use of limited resources.

26/07/2024

Screening test evaluations are essential in determining the effectiveness of medical tests in identifying a condition within a population. Two key metrics in these evaluations are **sensitivity** and **specificity**.

**Sensitivity** refers to the ability of a test to correctly identify those with the disease (true positives). A highly sensitive test minimizes false negatives, meaning it is less likely to miss cases of the disease. Sensitivity is crucial when the consequences of missing a case are severe, such as in the early detection of cancer.

**Specificity**, on the other hand, measures the test's ability to correctly identify those without the disease (true negatives). A highly specific test minimizes false positives, reducing the likelihood of mistakenly diagnosing someone as having the condition when they do not. This is particularly important in situations where a false positive result could lead to unnecessary stress, further testing, or treatment.

Together, sensitivity and specificity provide a comprehensive view of a test's accuracy, helping healthcare professionals choose the most appropriate screening tools for different conditions and populations.

08/07/2024

The QALY is a measure used in healthcare to assess the value and cost-effectiveness of medical treatments. It combines both the quality and quantity of life lived.Key points about QALYs:

QALYs measure the value of a health outcome by combining quality and length of life. One QALY equals one year of life in perfect health.

QALYs are calculated by multiplying the quality of life score (utility value) by the time spent in that health state.

QALYs allow comparison of the cost-effectiveness of different treatments. Treatments that provide more QALYs per dollar are considered more cost-effective.

QALYs have been criticized for oversimplifying how patients assess outcomes, and potentially discriminating against those with disabilities. But they remain an important tool for healthcare decision-making.

05/07/2024

Hypercalcemia is a condition where the level of calcium in the blood is higher than normal, typically above 2.6 mmol/L. It can be caused by various factors such as overactive parathyroid glands, cancer, too much vitamin D, and certain medications like thiazide diuretics and lithium. Symptoms can be mild, like feeling tired or constipated, but can also be more severe, causing frequent urination, kidney stones, mood changes, and heart problems. To diagnose hypercalcemia, doctors measure calcium levels in the blood and may also check parathyroid hormone (PTH) levels, vitamin D levels, and perform imaging tests to find the cause.

Treating hypercalcemia involves addressing the underlying cause and lowering the calcium levels in the blood. Initial treatment usually includes drinking plenty of fluids to help the kidneys get rid of excess calcium. In more severe cases, medications like bisphosphonates, calcitonin, or steroids might be used. If hypercalcemia is due to an overactive parathyroid gland, surgery may be needed. It's important to monitor and manage any complications like kidney problems, weak bones, and heart issues. Understanding the different causes and symptoms of hypercalcemia is crucial for proper diagnosis and treatment.

02/07/2024

Gallstones are thought to be caused by an imbalance in the chemical make-up of bile inside the gallbladder. Bile is a liquid produced by the liver to help digestion.

It's unclear what causes the chemical imbalance, but gallstones can form if there are unusually high levels of:

-cholesterol inside the gallbladder (about 4 out of 5 gallstones are made of cholesterol)
-a waste product called bilirubin inside the gallbladder (about 1 in 5 gallstones is made of bilirubin)

These chemical imbalances cause tiny crystals to develop in the bile.

These can gradually grow (often over many years) into solid stones that can be as small as a grain of sand or as large as a pebble.

Sometimes only 1 stone will form, but there are often several at the same time.

Gallstones are more common if you:
-are female, particularly if you have had children, are taking the combined pill, or are undergoing high-dose oestrogen therapy
-are overweight or obese
-are aged 40 years or older (the older you are, the more likely you are to develop gallstones)
-have a condition that affects the flow of bile (such as cirrhosis, primary sclerosing cholangitis, or obstetric cholestasis)
-have Crohn's disease or irritable bowel syndrome (IBS)
-have a close family member who's also had gallstones
-have recently lost weight (from either dieting or weight loss surgery)
-are taking an antibiotic called ceftriaxone

01/07/2024

Using AI for medical issues can be risky because of something called AI hallucinations. This happens when AI gives information that seems correct but is actually wrong. In medicine, this can lead to wrong diagnoses and treatments, which can be very dangerous. AI doesn’t understand the way human doctors do and can make mistakes based on bad data. So, relying only on AI for medical advice can put your health at serious risk.

Another problem is that many people might not notice when AI gives wrong information. This can lead to trusting bad advice and making poor health decisions. In serious health situations, this can be life-threatening. Always consult with real doctors and use AI as a helpful tool, not your main source of medical advice. This way, you can avoid the dangers of AI mistakes and make sure you get safe and accurate health care.

Drmichaelhanrahan