Iatrogenesis in older adults

John O. Barr and Timothy l. Kauffman

Overview

Iatrogenesis is defined as any injury or illness that occurs as a result of medical care (Taber’s Cyclopedic Medical Dictionary, 2013). An iatrogenic condition is a state of ill health or adverse effect caused by medical treatment; it usually results from a mistake made in diagnosis or treatment, and can also be the fault of any member of the healthcare team. The risk of iatrogenesis in individuals over the age of 65 is twice as high as that of a younger person (Gurwitz et al., 1994) and iatrogenic complications may be more severe in the elderly (Merck Manual, 2013). A sentinel report from the Institute of Medicine attributed most errors not to negligence or misconduct, but to system-related problems (Institute of Medicine, 1999).

From 2007 to 2009, 708 642 patient safety events were reported to have contributed to the deaths of 79 670 hospitalized Medicare beneficiaries in the United States of America (Healthgrades, 2011). Iatrogenic events have been estimated to affect 65% of nursing home residents annually and are likely to have negative impacts on older individuals residing in assisted living facilities as well (Mitty, 2010). Adverse drug reactions from prescription medications result from incorrect ordering and administration of dosages, and from polypharmacy in the elderly. Other problematic errors may be based on misreading test results, or on the ambiguous presentations of symptoms, a hallmark of aging (Lantz, 2002; Agency for Healthcare Research and Quality, 2004; Mitty, 2010). For 2011, 874 116 adverse event reports for drugs and therapeutic biologic products were received by the Food and Drug Administration, up from 370 240 reports in 2003 (FDA, 2012). It is estimated that 27% of adverse drug events in primary care and 42% in long-term care are preventable (American Geriatrics Society, 2012).

Hospitalization increases the risk for nosocomial infections, transfusion reactions, polypharmacy and immobility. Mobility is critical for well-being and quality of life in the elderly individual. Surgical and medical interventions may lead to complications because of anesthesia or fluid overload (Merck Manual, 2013). Older patients often arrive at hospital without medications or an appropriate list of prescribed drugs, meaning that scheduled doses may be missed for hours or days. Hospitalized older adults are especially at risk for ‘cascade iatrogenesis’, the development of multiple complications initiated by a seemingly innocuous initial event (Thomlow et al., 2009).

A host of factors augment the risk of the elderly suffering an iatrogenic condition. The presence of multiple chronic diseases increases the possibility that the treatment of one problem may have a negative impact on another. For example, the use of a nonsteroidal anti-inflammatory (NSAID) medication in the treatment of arthritis may exacerbate heart failure or chronic gastritis. Fragmentation of health delivery into many specialties may lead to changes being made in therapeutic interventions without adequate communication among caregivers.

A number of initiatives have been suggested to prevent iatrogenesis, especially in the frail elderly, including: use of case managers to coordinate services; judicious involvement of a geriatric interdisciplinary team for complex cases; consultation with a pharmacist; establishment of specific acute care units for the elderly; and preparation of advance directives, including designation of a proxy for medical decisions (Merck Manual, 2013). In an effort to promote safer healthcare, the Agency for Healthcare Research and Quality has published ‘20 Tips to Help Prevent Medical Errors’, presented in Box 56.1. This fact sheet informs patients and their family members about practical steps that they can take to prevent medical errors, thus ensuring safer healthcare.

Box 56.1

20 Tips to help prevent medical errors

What You Can Do to Stay Safe

The best way you can help to prevent errors is to be an active member of your healthcare team. That means taking part in every decision about your healthcare. Research shows that patients who are more involved with their care tend to get better results.

Medicines

1. Make sure that all of your doctors* know about every medicine you are taking. This includes prescription and over-the-counter medicines and dietary supplements, such as vitamins and herbs.

2. Bring all of your medicines and supplements to your doctor visits. ‘Brown bagging’ your medicines can help you and your doctor talk about them and find out if there are any problems. It can also help your doctor keep your records up to date and help you get better quality care.

3. Make sure your doctor knows about any allergies and adverse reactions you have had to medicines. This can help you to avoid getting a medicine that could harm you.

4. When your doctor writes a prescription for you, make sure you can read it. If you cannot read your doctor’s handwriting, your pharmacist might not be able to either.

5. Ask for information about your medicines in terms you can understand – both when your medicines are prescribed and when you get them:

• What is the medicine for?

• How am I supposed to take it and for how long?

• What side-effects are likely? What do I do if they occur?

• Is this medicine safe to take with other medicines or dietary supplements I am taking?

• What food, drink, or activities should I avoid while taking this medicine?

6. When you pick up your medicine from the pharmacy, ask: Is this the medicine that my doctor prescribed?

7. If you have any questions about the directions on your medicine labels, ask. Medicine labels can be hard to understand. For example, ask if ‘four times daily’ means taking a dose every 6 hours around the clock or just during regular waking hours.

8. Ask your pharmacist for the best device to measure your liquid medicine. For example, many people use household teaspoons, which often do not hold a true teaspoon of liquid. Special devices, like marked syringes, help people measure the right dose.

9. Ask for written information about the side-effects your medicine could cause. If you know what might happen, you will be better prepared if it does or if something unexpected happens.

Hospital stays

10. If you are in a hospital, consider asking all healthcare workers who will touch you whether they have washed their hands. Hand washing can prevent the spread of infections in hospitals.

11. When you are being discharged from the hospital, ask your doctor to explain the treatment plan you will follow at home. This includes learning about your new medicines, making sure you know when to schedule follow-up appointments, and finding out when you can get back to your regular activities.
It is important to know whether or not you should keep taking the medicines you were taking before your hospital stay. Getting clear instructions may help prevent an unexpected return trip to the hospital.

Surgery

12. If you are having surgery, make sure that you, your doctor and your surgeon all agree on exactly what will be done.
Having surgery at the wrong site (for example, operating on the left knee instead of the right) is rare. But even once is too often. The good news is that wrong-site surgery is 100% percent preventable. Surgeons are expected to sign their initials directly on the site to be operated on before the surgery.

13. If you have a choice, choose a hospital where many patients have had the procedure or surgery you need. Research shows that patients tend to have better results when they are treated in hospitals that have a great deal of experience with their condition.

Other steps

14. Speak up if you have questions or concerns. You have a right to question anyone who is involved with your care.

15. Make sure that someone, such as your primary care doctor, coordinates your care. This is especially important if you have many health problems or are in the hospital.

16. Make sure that all your doctors have your important health information. Do not assume that everyone has all the information they need.

17. Ask a family member or friend to go to appointments with you. Even if you do not need help now, you might need it later.

18. Know that ‘more’ is not always better. It is a good idea to find out why a test or treatment is needed and how it can help you. You could be better off without it.

19. If you have a test, do not assume that no news is good news. Ask how and when you will get the results.

20. Learn about your condition and treatments by asking your doctor and nurse and by using other reliable sources. For example, treatment options based on the latest scientific evidence are available from the Effective Health Care website (www.effectivehealthcare.ahrq.gov/options). Ask your doctor if your treatment is based on the latest evidence.

* Note: the term ‘doctor’ refers to the person who helps you manage your healthcare.

Adapted with permission from 20 Tips to Help Prevent Medical Errors. Patient Fact Sheet. AHRQ Publication No. 11-0089, September 2011. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/consumer/20tips.htm.

An array of both voluntary and mandatory adverse event reporting systems in countries around the world has been summarized, and guidelines for reporting and learning systems have been drafted by the World Alliance for Patient Safety (2005). Not meant to be punitive (which likely would inhibit reporting), these systems are intended to enhance patient safety by facilitating learning from healthcare system failures and by taking action to make corrective changes.

This chapter focuses on iatrogenesis related to adverse drug reactions and immobility, and offers suggestions for proactively preventing these conditions.

Adverse drug reactions

Polypharmacy is a complex multifactorial issue. Individuals aged 65 and over take 33–40% of all prescription medications in the US (Lantz, 2002) and more than 50% of the over-the-counter medicines. Approximately four out of five people in this age group take at least one drug daily (Beyth & Shorr, 2002). Zhan and associates (2001) reported that one out of five people aged 65 or older who lived in the community was taking at least one prescription drug that was inappropriate as determined by an expert panel. These researchers recommend that the following medications be avoided in the elderly: barbiturates, flurazepam, meprobamate, chloropropamide, meperidine (pethidine), pentazocine, trimethobenzamide, belladonna alkaloids, dicyclomine, hyoscyamine and propantheline.

Age-related physiological changes affect the absorption, distribution, metabolism and elimination of drugs. Stomach changes, such as increased pH or altered motility, may reduce drug absorption. Decreases in total body water and lean body mass, as well as increases in total body fat, can alter drug distribution. Diminution of liver mass and blood flow may alter drug metabolism, and reductions in renal plasma flow and glomerular filtration rate (GFR) decrease drug elimination via the kidney (Beyth & Shorr, 2002).

A complication of type 2 diabetes mellitus is chronic renal failure. Corsonello et al. (2005) reported that chronic renal failure may be unrecognized or ‘concealed’ and may contribute to an adverse drug reaction (ADR). A standard method for determining renal failure is detection of elevated serum creatinine; however, in the elderly, it may be within the normal range because of the decreased GFR. Thus, renal failure may be ‘concealed’ and subsequently lead to an ADR, especially in patients using hydrosoluble drugs (sulfonylureas, metformin, digitalis, angiotensin-converting enzyme [ACE] inhibitors, insulin, diuretics, antibiotics such as penicillins and cephalosporins, and NSAIDs). In their study of 2257 hospitalized patients with type 2 diabetes mellitus, more than 16% had concealed renal failure and more than 10% of all patients had ADRs.

Individuals with dementia are especially vulnerable to ADRs because of an increased availability of protein-bound agents (because of loss of lean body mass, and reduced albumin) such as antidepressants and antipsychotics (American Geriatrics Society, 2012). Secondary parkinsonism is often caused by medications, including antipsychotics (Merck Manual, 2013). Tardive dyskinesia is a drug-induced movement disorder that is usually caused by antipsychotics such as haloperidol. It is characterized by abnormal involuntary movements involving the tongue and lips, e.g. chewing motions, and produces a feeling of motor restlessness and not wanting to stay still. As with all ADRs, a change of prescription drugs is helpful, if at all possible. Additionally, antipsychotics, as well as beta blockers, carbidopa–levodopa, diuretics and sedative–hypnotics (benzodiazepines), may cause sleep disturbances in elderly individuals.

In recent years, testosterone replacement has been used to treat secondary hypogonadism and the related male problems of sarcopenia and changes in libido, bone mass and visuospatial cognition. Calof et al. (2005) performed a meta-analysis of clinical trials to evaluate the risks of ADRs in men over the age of 45 who undergo testosterone replacement. They reported that this medical intervention was significantly associated with higher rates of prostate cancer, elevated prostate-specific antigen and prostate biopsies. Hematocrit was also elevated and warrants monitoring in men taking testosterone. There were no significant differences between the testosterone group and placebo group in the frequency of sleep apnea or cardiovascular events.

Quiceno and Cush (2005) have noted that medication-related iatrogenic events may masquerade as rheumatic disorders. Although rare, myopathic syndromes associated with the use of statins include myopathy, myalgia, myositis and rhabdomyolysis. Drugs that induce lupus include procainamide, hydralazine, methyldopa, quinidine and chlorpromazine. Gout, most commonly produced by underexcretion of uric acid, is associated with ethanol use, diuretics, low-dose salicylate, cyclosporin (ciclosporin), ethambutol, pyrazinamide, levodopa and nicotinic acid. Arthralgias can be the result of anti-infectives (e.g. quinolones and vaccines), biological agents (e.g. interferons and growth factors), supplements (e.g. fluoride and vitamin A), lipid-lowering statins and fibrates, cardiac drugs (e.g. quinidine, propranolol, acetabulol, nicardipine) and hormonal agents (e.g. raloxifene, tamoxifen, letrozole).

The use of medications in the elderly is complex and is associated with iatrogenesis, as noted above. Antidepressant or analgesic medications have also been associated with falls in ambulatory frail elderly individuals (American Geriatrics Society, 2012). However, medications that carry risks of ADRs may also provide benefits. Won et al. (2006) reported that the use of short- or long-acting opioids in nursing home residents was not associated with an increased risk of falls, depression, constipation, delirium, dehydration or pneumonia. They found that the use of pain medications improved functional status and social engagement.

Actions that can be taken to limit drug-related iatrogenesis have been long known, as outlined by Stolley et al. (1991). These include educating patients and staff about drug effects and potential problems; carrying out a formal drug review by a gerontological nurse and pharmacist; and taking an accurate drug history, which includes a thorough assessment of drug allergies, possible drug borrowing and proper drug use by patients.