CMAJ/JAMC Body and mind
Corps et esprit

 

Revisiting the O complex: urinary incontinence, delirium and polypharmacy in elderly patients

David B. Hogan, MD

CMAJ 1997;157:1071-7

[ résumé ]

Dr. Hogan is Professor and the Brenda Strafford Chair in Geriatric Medicine, University of Calgary, Calgary, Alta.

This article has been peer reviewed.

Reprint requests to: Dr. David B. Hogan, Health Sciences Centre, 3330 Hospital Dr. NW, Calgary AB T2N 4N1; fax 403 283-1089; dhogan@acs.ucalgary.ca

© 1997 Canadian Medical Association (text and abstract/résumé)

Contents
Abstract

Urinary incontinence, delirium and polypharmacy are common, challenging problems encountered in elderly patients. Review of the literature shows that these conditions are interrelated. For example, polypharmacy can lead to delirium, which, in turn, can lead to urinary incontinence. The drugs prescribed for urinary incontinence can precipitate delirium or contribute to polypharmacy. The underlying causes for these problems in elderly patients are frequently complex, and management in turn must often be multifactorial. The occurrence of these problems should lead to careful evaluation followed by thoughtful, responsive treatment. Brief updates are given with recommendations for management directed at primary care physicians.

Résumé

L'incontinence urinaire, le délire et la polypharmacie sont des problèmes répandus et difficiles chez les patients âgés. Une recension des écrits démontre que les problèmes sont reliés. Par exemple, la polypharmacie peut provoquer le délire qui, en retour, peut entraîner l'incontinence urinaire. Les médicaments prescrits contre l'incontinence urinaire peuvent provoquer le délire ou contribuer à la polypharmacie. Comme les causes de ces problèmes sont souvent complexes, la prise en charge doit souvent tenir compte de facteurs multiples. Ces problèmes devraient entraîner une évaluation prudente suivie d'un traitement réfléchi et adapté. On présente des mises à jour et des recommandations sur la prise en charge qui s'adressent aux médecins de première ligne.

[ Contents ]

Introduction

A pioneer of Canadian geriatrics, Ronald Cape, wrote about the O complex in his book Aging: Its Complex Management.1 He felt that falling, confusion, incontinence, homeostatic disturbance and iatrogenic illness formed a quintet of interrelated clinical challenges. The name he chose, the O complex, comes from the symbol of the Olympic Games, which he used to represent these problems and their interrelationship. Cape felt that these problems represented "the core of knowledge unique to the medicine of the very old."1 Thirteen years of practice as a consultant in geriatric medicine has confirmed to me that they are both common -- and the older the patient, the more common they are -- and interrelated.

These problems are arguably dealt with inadequately by physicians. For example, a Canadian study looking at continuing medical education needs in geriatrics showed that 70.8% of health care workers other than physicians felt that physicians were inadequately trained to deal with incontinence.2 In this article I will provide necessarily brief updates for the primary care physician on the assessment and management of urinary incontinence (the most common form of incontinence encountered), delirium and polypharmacy (because adverse drug reactions are the commonest type of iatrogenic illnesses encountered). Because of limited space, falls could not be dealt with in this article. Recent clinical research has underscored the utility of exercise and multidimensional, targeted (to risk factors for falls) evaluation in the patient's home coupled with individualized interventions in decreasing the likelihood of further falls.3­6

[ Contents ]

Urinary incontinence

Urinary incontinence occurs when there is involuntary loss of urine that is a social or hygienic problem and is objectively demonstrable.7 It has been reported that 15% to 30% of older people in the community and up to 50% of residents of long-term care facilities have this problem.8,9 Women are more prone to urinary incontinence than men.

Urge incontinence is the most common type encountered. Large amounts of urine may be lost, typically preceded by a sense of urgency. This incontinence arises from involuntary bladder contractions, which increase intravesical pressures above urethral closure pressures. In a subtype of urge incontinence often found in frail elderly people, the hyperactivity is accompanied by impaired contractility of the bladder.9 With stress incontinence the loss of urine classically occurs with activities that increase intra-abdominal pressure (e.g., coughing). The underlying cause is urethral sphincter incompetence. Stress incontinence is found predominantly in women. Frequent or constant loss of small amounts of urine accompanied by a poor stream and a sense of incomplete emptying suggests overflow incontinence. This may occur because of outflow obstruction (e.g., from benign prostatic hypertrophy) or bladder atony (e.g., from autonomic neuropathy). Continuous incontinence can also occur as a result of fistulas involving the bladder. Many patients have a mixed etiology; stress with urge incontinence and urge with overflow incontinence are particularly common. With so-called functional incontinence the primary problem is not with the bladder or sphincter; rather, the incontinence arises because the patient is unable to get to a toilet in time. Several conditions, such as delirium, urinary tract infection and atrophic urethritis, as well as certain drugs may worsen or precipitate incontinence in someone who is "just managing." It must be recognized that there is considerable overlap in symptoms among the various types of incontinence. History by itself is a suspect guide for diagnosis.10,11

Assessment

Patients often do not report urinary incontinence and may even conceal it because of embarrassment. This is unfortunate, because treatment can usually provide at least partial relief. In the initial evaluation patients should be asked about the duration and mode of onset of the incontinence. There may be a clear association with a particular event, such as the prescription of a medication. Severity can be ascertained by obtaining a bladder record (or voiding diary) and asking about frequency (both day and night), the number of pads used per day and how often clothes and bedding have to be changed. The effect on the patient's activities and relationships should be assessed. Urologic symptoms may suggest one of the commoner types of incontinence. Obstetric/gynecologic, medical and medication histories should be obtained. Examinations of the abdomen (feeling for bladder distension and other masses), rectum (checking for prostate size, fecal impaction and anal tone) and vagina (looking for atrophy, prolapse and fistulas) should be performed. A manoeuvre to provoke stress incontinence (looking for leakage while the patient coughs or strains with a full bladder) can be helpful. Mobility, dexterity and cognition must be evaluated. Ascertaining the presence of residual urine after voiding, either by catheterization or by a bladder ultrasound examination, can determine the need for further evaluation and help plan treatment.

One should obtain at least a urinalysis, urine culture and a creatinine (or urea) level in all patients presenting with urinary incontinence. Referral to a specialist or for urodynamic studies, or both, is indicated if there is uncertainty about the cause, if the patient wishes it, if there are symptoms suggestive of mixed stress and urge incontinence, if there is considerable postvoid urine retention (200 mL or more), before incontinence surgery, after urologic or gynecologic surgery, in the presence of neurologic conditions (e.g., multiple sclerosis) or if the incontinence does not respond to the initial treatment plan.

Several algorithms have been developed for the diagnostic evaluation of urinary incontinence.12 A simplified approach is outlined in Table 1. Transient and serious causes can generally be detected by the assessment outlined above. Detecting overflow incontinence by looking for residual urine after the patient has voided is the next step. If this is ruled out, for women the diagnosis is likely urge or stress incontinence.9 The treatment approaches to these 2 types of incontinence do overlap.

Management

Urinary incontinence can often be effectively managed with simple measures.8,9,13­15 Patients should be encouraged to have a moderate fluid intake. There should be restricted consumption of caffeine-containing drinks. Aggravating or precipitating factors (including obesity) should be dealt with if possible. Eradicating bacteriuria, however, has not been found to affect the severity of chronic urinary incontinence in nursing home residents, and the practice of treating asymptomatic bacteriuria in this population is not justified.16 All drugs being taken must be reviewed. Antidepressants and antihistamines taken regularly may worsen urinary symptoms and decrease flow rates in men.17 Diuretics can precipitate or worsen incontinence.12 Other drugs to be wary of include alcohol, caffeine, anticholinergics, antiparkinsonian medications, sedatives or hypnotics, disopyramide, narcotics, calcium-channel blockers, *-adrenergic agents and ß-adrenergic agonists.12 Continence aids (e.g., urinals, commodes, aids in the toilet and protective devices) are often useful treatment adjuncts.

Bladder retraining (or prompted voiding for cognitively impaired patients) is the mainstay of treatment for urge incontinence and may be useful in patients with stress incontinence.9 Pelvic floor exercises can also help in women.18 Drug therapy (e.g., imipramine hydrochloride, oxybutynin chloride and propantheline bromide) should be reserved for cases that do not respond adequately. Oxybutynin is the drug used most often. Although its effectiveness is open to question, it does appear to decrease frequency and produce subjective relief.19 Urinary retention may occur, especially in patients with impaired bladder contractility.9 For stress incontinence, pelvic floor exercises and estrogen therapy are often used initially. Alpha-adrenergic agonists (which include phenylpropanolamine hydrochloride and imipramine hydrochloride, as it has *-adrenergic agonist activity) can be used, often in combination with estrogen. Surgery to elevate and stabilize the urethrovesical junction is generally reserved for patients with severe symptoms that have not responded to more conservative measures. Overflow incontinence caused by prostate hypertrophy may respond to treatment with *-adrenergic antagonists or 5-*-reductase inhibitors, or both. All such patients should be considered for surgery but not rushed into it. Patients with bladder atony may require intermittent catheterization. For functional incontinence a comprehensive rehabilitation program may be of the greatest utility.

[ Contents ]

Delirium

With delirium intellectual function deteriorates abruptly. The differential diagnosis includes psychiatric disorders, including depression20 and dementia.21 Delirium can be caused by systemic illnesses, central nervous system (CNS) diseases, exogenous chemical agents and withdrawal from a substance of abuse, alone or in combination. The list of potential specific causes is lengthy. Drug- and sepsis-associated delirium are possibly the commonest types found in elderly people. Fluid and electrolyte abnormalities are frequently encountered as contributing factors.

This presentation is commonly encountered in older inpatients. About 10% to 20% of elderly people admitted to hospital are delirious, and a further 10% to 33% experience delirium while in hospital.21 Postoperative delirium occurs in about one-third of elderly patients undergoing surgery.22

The underlying pathophysiology is poorly understood. It represents a global failure of brain metabolism. Delirium arises from an interplay of predisposing and precipitating factors. Postoperative delirium has been associated with increased age, pre-existing cognitive impairment, perioperative biochemical abnormalities, postoperative polypharmacy (defined as the use of 5 or more medications), preoperative use of anticholinergic drugs and cardiac surgery.22,23 Marcantonio and colleagues20 found 7 preoperative and operative factors that predicted the occurrence of delirium in patients undergoing surgery other than cardiac surgery and developed a scoring mechanism to classify patients (Table 2). They assigned 1 point for each factor except for abdominal aortic aneurysm repair, which received a score of 2. If the total score was 0 the incidence of postoperative delirium was 2%, if the score was 1 or 2 the incidence was 11%, and if the score was 3 or greater the incidence was 50%.

In medical patients Inouye and associates25 found a number of predisposing factors for the development of delirium (Table 2). If none was present the incidence of delirium was 1% to 3%, if 1 or 2 were present the incidence was 16% to 23%, and if 3 or 4 were present the incidence was 32% to 83%. Precipitating factors identified by the same group are also shown in Table 2.26 The incidence of delirium when none of these factors was present was 3% to 4%, if 1 or 2 were present the incidence was 20%, and if 3 or more were present the incidence was 35% to 59%. Increased numbers of both predisposing and precipitating factors increased the likelihood of delirium. They seemed to work in an independent but cumulative manner.

Assessment

Delirium is often unrecognized by physicians.27 A number of instruments can screen for this problem.28 An easy one to use is the Confusion Assessment Method.29 With this method the presence of acute onset and a fluctuating course (for the cognitive impairment) plus inattention coupled with either disorganized thinking or an altered level of consciousness are required to suggest the presence of delirium.

Management

Management is empirical. Preventive strategies include identifying patients at high risk; cautiously using psychotropic medications and narcotics; ensuring adequate hydration, nutrition and oxygenation; promptly addressing medical concerns; and paying attention to the patient's physical environment. Patients at high risk require close monitoring and early, vigorous correction of abnormalities found on laboratory investigations. Postoperative delirium has been found to be associated with the postoperative use of meperidine hydrochloride and benzodiazepines (especially those with a long half-life or if used at a higher dosage).30 Meperidine has both an active metabolite (normeperidine), which can accumulate, and more anticholinergic activity than other narcotics. It seems reasonable to avoid meperidine and use other narcotics, such as morphine, in the care of elderly patients. There has been one report of an apparently successful program to reduce the incidence of postoperative delirium in patients with hip fractures.31 The program consisted of a careful preoperative evaluation, routine anticoagulation therapy, oxygen administration, expeditious surgery and postoperative care by a geriatrician.

If delirium occurs one searches for the specific underlying cause(s) and deals with it (them) if at all possible. Routine laboratory studies would include a complete blood count, determination of the serum electrolyte levels and arterial blood gas values (or pulse oximetry), tests of renal function, a liver profile and screening for sepsis (chest radiography and urine culture).21,30 Neuroimaging should be done in patients who are felt to have a structural brain lesion. Delirious patients are more likely to show ventricular dilation, cortical atrophy and focal changes (especially in the right hemisphere) on neuroimaging than unmatched control subjects.32 Electroencephalographic abnormalities (e.g., predominant theta or delta waves, triphasic waves and suppression of voltages) are common and correlate with severity. Further investigations will depend on the findings of the initial assessment.

Supportive care includes hydration, nutrition and oxygenation. Nonessential drugs should be eliminated. Nursing interventions involve providing a tranquil environment, modifying sensory input, providing frequent reorientation, rectifying sensory impairments if possible, trying to provide familiarity (e.g., requesting family members to stay with the patient), simplifying communication, and encouraging self-care and other personal activities while ensuring safety.33 Physical restraints should be avoided if at all possible because they may precipitate delirium or worsen agitation.26

If drugs are required for agitation or psychotic features, high-potency neuroleptics are favoured. Specific target symptom(s) should be identified and specific goal(s) set for therapy. The symptom(s) should be monitored carefully, with continued efforts to reduce and eventually stop the neuroleptics. Haloperidol is currently the preferred neuroleptic because of its familiarity and relative lack of anticholinergic, sedative and cardiorespiratory effects. Oral administration is preferred, although it can be given intramuscularly or intravenously. Initial doses as low as 0.5 mg may be effective in elderly patients. In severely agitated patients rapid loading can be done by doubling each successive dose at 30-minute intervals until the agitation is controlled. A maintenance dose of one-half of the total loading dose could then be administered in divided doses over the next day, with gradual tapering subsequent to this.17 Intermediate-acting benzodiazepines (e.g., lorazepam, at an initial dose of 1 to 2 mg given orally or 0.5 to 1.0 mg intramuscularly) can also be used to sedate an agitated patient, especially if the delirium is associated with withdrawal from a sedative or hypnotic.34 Although prompt recognition and treatment appear to be worthwhile, a study of a structured program to do just this could not show clinically significant benefits.33

A meta-analysis of the prognosis for elderly inpatients with delirium showed that 1 month after hospital admission 46.5% were in institutions (as compared with 18.3% of control subjects), 14.2% had died (as compared with 4.8% of control subjects), and 54.9% had improved mentally.35 At 6 months 43.2% were in institutions (8.3% of control subjects), and 22.2% had died (10.6% of control subjects). Delirious older patients often have longer hospital stays, are more likely to experience a functional decline and have cognitive impairment for a longer time.24,36­38

[ Contents ]

Polypharmacy

Data from the prescription drug benefit program in British Columbia show that 84% of the elderly population in that province receive at least 1 prescription over a 1-year period.39 In 1993 prescription and over-the-counter medications accounted for 15.1% of the total expenditures for health care in Canada and represented the area with the fastest growth.40 What is driving these cost increases? Anderson and collaborators41 found that during the 1980s 34% of the increase in drug costs for older people in BC was accounted for by new drugs, 24% by increases in age-specific rates of use, 21% by increases in prices for old drugs, and only 14% by increases in the elderly population. Efforts to control public expenditures for drugs in Canada have included the establishment of the Patented Medicines Prices Review Board,40 drafting of pharmacoeconomic guidelines,40 adoption of restricted provincial formularies,40,42 rules for drug substitution,40 rules for price selection,40 changes in copayment amounts or deductibles for publicly funded drug benefit plans and reference-based pricing.43­45 The rate of increase in drug expenditures is slowing down, possibly as a result of one or more of these measures.46

Increasing attention in our country has been directed to the issue of evaluating the appropriateness of prescriptions, trying to determine predictors of poor prescribing practices, and looking for potentially adverse drug interactions.47­53 Appropriate prescribing is a complex task. Drugs should be prescribed only for an acceptable indication at a correct dose and frequency for an acceptable duration. Care must be taken to avoid inappropriate duplication of drugs, potentially adverse drug­disease interactions and potentially adverse drug­drug interactions. Even when used appropriately, bad things can happen with the use of medications. For example, a "prescribing cascade" can occur, in which the use of one drug leads to the use of another to deal with the side effects of the first.51,54

Research suggests that inappropriate prescribing is common in Canada.47,52,55,56 Although most attention has been focused on overuse of medications, there is evidence that certain medications are underused in older patients.57 There appears to be significant warfarin underuse in the treatment of elderly patients with atrial fibrillation58 and underuse of ß-blockers in elderly survivors of acute myocardial infarction.59 No patient should be denied a medication with a favourable benefit­risk ratio solely because of age.

Polypharmacy can be defined as any drug regimen with at least one unnecessary medication.60 Excess use of medications is a serious, preventable public health problem. It increases the risk of iatrogenic illness, the likelihood of noncompliance and both direct and indirect (to deal with the drug-related illness) health care costs.60

A number of system-level initiatives may help in decreasing the prevalence of this problem. Trying to ensure that patients have a single primary care physician and a single dispensing pharmacy appears worthwhile.50 Drug use reviews are formal programs designed to assess data on drug use against explicit, prospective standards and, as necessary, introduce remedial strategies to achieve some desired end.40 Both retrospective (using archival data on drug prescribing) and prospective (point-of-prescribing or dispensing analysis) programs have been implemented. Efforts have been made to define inappropriate practices in a rigorous manner.61 The interventions to improve the identified problematic practices have typically been educational in nature. The most effective method appears to be one-on-one education for physicians by trained pharmacists ("academic detailing").56,62

A strategy to reduce polypharmacy for practising physicians is outlined in Table 3.54,60,63,64 The appropriate use of drugs, however, involves more than physicians. The triad most directly involved is the prescribing physician, the dispensing pharmacist and the patient or consumer. A joint statement by the CMA and the Canadian Pharmaceutical Association on enhancing the quality of drug therapy has been published.65 The role of consumers is critical because they are the final arbitrator of what is actually taken.66

[ Contents ]

Conclusion

What becomes increasingly clear after a review of the literature is the interrelationship among the problems reviewed. Polypharmacy can lead to delirium, which, in turn, can lead to incontinence. The drugs prescribed for incontinence can precipitate delirium or lead to polypharmacy. Polypharmacy is an important public health issue. In Alberta the 4 categories of drugs most frequently prescribed for older people are cardiovascular agents, CNS drugs, gastrointestinal drugs, and hormones and synthetic substitutes.67 The use of CNS agents (which include benzodiazepines, antidepressants, antipsychotics and analgesics) is particularly problematic in elderly patients. In 1995, there were over 1 million claims for CNS drugs by elderly people in Alberta -- over 4 claims per person.

Falls, urinary incontinence, delirium and sensitivity to adverse effects from drugs may have an underlying, common predisposing risk factor -- possibly what Cape1 referred to as a homeostatic disturbance or what we would now call frailty. The underlying causes in elderly patients are frequently complex, and management in turn must often be multifactorial. The problems reviewed in this article should never be blamed on aging alone. Their occurrence should lead to careful evaluation followed by thoughtful, responsive treatment.

[ Contents ]

References

  1. Cape R. Aging: Its complex management. Hagerstown (MD): Harper & Row Publishers; 1978. p. 81-2.
  2. Pereles L, Russell ML. Needs for CME in geriatrics: part 1. Perceptions of patients and community. Can Fam Physician 1996;42:437-45.
  3. Province MA, Hadly EC, Hornbrook MC, Lipsitz LA, Miller JP, Mulrow CD, et al. The effects of exercise on falls in elderly patients. JAMA 1995;273:1341-7.
  4. Tinetti ME, Baker DI, McAvay G, Claus EB, Garrett P, Gottschalk M, et al. A multifactorial intervention to reduce the risk of falling among elderly people living in the community. N Engl J Med 1994;331:821-7.
  5. King MB, Tinetti ME. Falls in community-dwelling older persons. J Am Geriatr Soc 1995;43:1146-54.
  6. NHS Centre for Reviews and Dissemination and Nuffield Institute for Health. Preventing falls and subsequent injury in older people. Eff Health Care 1992;2(April):1-16.
  7. Abrams P, Blaivas JG, Stanton SL, Anderson JJ. The standardization of terminology of lower urinary tract function. Scand J Urol Nephrol 1988;114(suppl):5-19.
  8. Chutka DS, Fleming KC, Evans MP, Evans JM, Andrews KL. Urinary incontinence in the elderly population. Mayo Clin Proc 1996;71:93-101.
  9. Resnick NM. Geriatric incontinence. Urol Clin North Am 1996;23:55-74.
  10. Summit RL, Stovall TG, Bent AE, et al. Urinary incontinence: correlation of history and brief office evaluation with multichannel urodynamic testing. Am J Obstet Gynecol 1992;166:1835-40.
  11. Jensen JK, Nielsen FR, Ostergard DR. The role of patient history in the diagnosis of urinary incontinence. Obstet Gynecol 1994;83(5 pt 2):904-10.
  12. Urinary Incontinence Guideline Panel. Urinary incontinence in adults: Clinical practice guideline. Rockville (MD): Agency for Health Care Policy and Research, Public Health Service; 1992. AHCPR publ no 92-0038.
  13. O'Brien J, Austin M, Sethi P, Oboyle P. Urinary incontinence: prevalence, need for treatment and effectiveness of intervention by a nurse. BMJ 1991;303:1308-12.
  14. Seim A, Sivertsen B, Eriksen BC, Hunskaar S. Treatment of urinary incontinence in women in general practice: observational study. BMJ 1996;312:1459-62.
  15. O'Brien J, Long H. Urinary incontinence: long term effectiveness of nursing intervention in primary care. BMJ 1995;311:1208.
  16. Ouslander JG, Schapira M, Schnelle JF, Uman G, Fingold S, Tuico E, et al. Does eradicating bacteriuria affect the severity of chronic urinary incontinence in nursing home residents? Ann Intern Med 1995;122:749-54.
  17. Su L, Guess HA, Girman CJ, Jacobsen SJ, Oesterling JE, Panser LA, et al. Adverse effects of medications on urinary symptoms and flow rate: a community-based study. J Clin Epidemiol 1996;49:483-7.
  18. Nygaard IE, Kreder KJ, Lepic MM, Fountain KA, Rhomberg AT. Efficacy of pelvic floor exercises in women with stress, urge, and mixed urinary incontinence. Am J Obstet Gynecol 1996;174:120-5.
  19. Szonyi G, Collas DM, Ding YY, Malone-Lee JG. Oxybutynin with bladder retraining for detrusor instability in elderly people. Age Ageing 1995;24:287-91.
  20. Farrell KR, Ganzini L. Misdiagnosing delirium as depression in medically ill elderly patients. Arch Intern Med 1995;155:1459-64.
  21. Francis J. Delirium in older patients. J Am Geriatr Soc 1992;40:829-38.
  22. Dyer CR, Ashton CM, Teasdale TA. Postoperative delirium: a review of 80 primary data-collection studies. Arch Intern Med 1995;155:461-5.
  23. Fisher BW, Gilchrest DM. Postoperative delirium in the elderly. Ann R Coll Physicians Surg Can 1993;26:358-62.
  24. Marcantonio ER, Goldman L, Mangione CM, Ludwig LE, Murara B, Haslauer CM, et al. A clinical prediction rule for delirium after elective noncardiac surgery. JAMA 1994;271:134-9.
  25. Inouye SK, Viscoli CM, Horwitz RI, Hurst LD, Tinetti ME. A predictive model for delirium in hospitalized elderly medical patients based on admission characteristics. Ann Intern Med 1993;119:474-81.
  26. Inouye SK, Charpentier PA. Precipitating factors for delirium in hospitalized elderly persons. JAMA 1996;275:852-7.
  27. Rockwood K, Cosway S, Stolee P, Kydd D, Carver D, Jarrett P, et al. Increasing the recognition of delirium in elderly patients. J Am Geriatr Soc 1994;42:252-6.
  28. Pompei P, Foreman M, Cassel CK, Alessi C, Cox D. Detecting delirium among hospitalized older patients. Arch Intern Med 1995;155:301-7.
  29. Inouye SK, van Dyck CH, Alessi CA, Balkin S, Siegel AP, Horwitz RI. Clarifying confusion: the Confusion Assessment Method. Ann Intern Med 1990;113:941-8.
  30. Marcantonio ER, Juarez G, Goldman L, Mangione CM, Ludwig LE, Lind L, et al. The relationship of postoperative delirium with psychoactive medications. JAMA 1994;272:1518-22.
  31. Gustafson Y, Brännström B, Berggren D, Ragnarsson JI, Sigaard J, Bucht G, et al. A geriatric­anesthesiologic program to reduce acute confusional states in elderly patients treated for femoral neck fractures. J Am Geriatr Soc 1991;39:655-62.
  32. Koponen H, Hurri L, Stenback U, Mattila E, Soininen H, Rukkinen PJ. Computed tomography findings in delirium. J Nerv Ment Dis 1989;177:226-31.
  33. Cole MG, Primeau FJ, Bailey RF, Bonnycastle MJ, Masciarelli F, Engelsmann F, et al. Systematic intervention for elderly inpatients with delirium: a randomized trial. CMAJ 1994;151:965-70.
  34. Rummans TA, Evans JM, Krahn LE, Fleming KC. Delirium in elderly patients: evaluation and management. Mayo Clin Proc 1995;70:989-98.
  35. Cole MG, Primeau FJ. Prognosis of delirium in elderly hospital patients. CMAJ 1993;149:41-6.
  36. Levkoff SE, Evans DA, Liptzin B, Cleary PD, Lipsitz LA, Wetle TT, et al. Delirium: the occurrence and persistence of symptoms among hospitalized patients. Arch Intern Med 1992;152:334-40.
  37. Murray AM, Levkoff SE, Wetle TT, Beckett L, Cleary PD, Schor JD, et al. Acute delirium and functional decline in the hospitalized elderly patient. J Gerontol 1993;48:M181-6.
  38. Rockwood K. The occurrence and duration of symptoms in elderly patients with delirium. J Gerontol 1993;48:M162-6.
  39. Anderson G, Kerluke K. Distribution of prescription drug exposures in the elderly: description and implications. J Clin Epidemiol 1996;49:929-35.
  40. Anis AH, Carruthers SG, Carter AO, Kierulf J. Variability in prescription drug utilization: issues for research. CMAJ 1996;154:635-40 [full text / résumé].
  41. Anderson GM, Kerluke KJ, Pulcins IR, Hertzman C, Barer ML. Trends and determinants of prescription drug expenditures in the elderly: data from the British Columbia Pharmacare Program. Inquiry 1993;30:199-207.
  42. Yakabowich MR, Keeley G, Montgomery PR. Impact of a formulary on personal care homes in Manitoba. CMAJ 1994;150:1601-7.
  43. McLaughlin PR. Reference based pricing for provincial drug benefit programs [editorial]. Can J Cardiol 1996;12:16.
  44. Woollard RF. Opportunity lost: a frontline view of reference-based pricing. CMAJ 1996;154:1185-8 [full text / résumé].
  45. Boulet AP, Tessier G. Reference-based pricing in British Columbia: implications for cardiologists -- an analysis. Can J Cardiol 1997;13:46-51.
  46. Buske L. Regulating the price of patented drugs. CMAJ 1997;156:1512 [full text / texte complet].
  47. Davidson W, Molloy DW, Somers G, Bedard M. Relation between physician characteristics and prescribing for elderly people in New Brunswick. CMAJ 1994;150:917-21.
  48. Thomson M, Smith WA. Prescribing benzodiazepines for noninstitutionalized elderly. Can Fam Physician 1995;41:792-8.
  49. Monette J, Tamblyn RM, McLeod PJ, Gayton DC, Laprise R. Do medical education and practice characteristics predict inappropriate prescribing of sedative­hypnotics for the elderly? Acad Med 1994;69(10 suppl):S10-2.
  50. Tamblyn RM, McLeod PJ, Abrahamowicz M, Laprise R. Do too many cooks spoil the broth? Multiple physician involvement in medical management of elderly patients and potentially inappropriate drug combinations. CMAJ 1996;154:1177-84 [abstract / résumé].
  51. Hogan DB, Campbell NRC, Crutcher R, Jennett P, MacLeod N. Prescription of nonsteroidal anti-inflammatory drugs for elderly people in Alberta. CMAJ 1994;151:315-22.
  52. Tamblyn RM, McLeod PJ, Abrahamowicz M, Monette J, Gayton DC, Berkson L, et al. Questionable prescribing for elderly patients in Quebec. CMAJ 1994;150:1801-9.
  53. Hogan DB, Campbell NRC, Jennett P, MacLeod N, Brant R. Increased use of cardiovascular medications in seniors prescribed non-ASA non-steroidal anti-inflammatory drugs. Clin Invest Med 1996;19:46-54.
  54. Rochon PA, Gurwitz JH. Drug therapy. Lancet 1995;346:32-6.
  55. Carter AO, Strachan D, Appiah Y. Physician prescribing practices: What do we know? Where do we go? How do we get there? CMAJ 1996;154:1649-53 [full text / résumé].
  56. Anderson GM, Lexchin J. Strategies for improving prescribing practice. CMAJ 1996;154:1013-7 [full text / résumé].
  57. Hogan DB, Ebly EM, Fung TS. Regional variations in use of potentially inappropriate medications by Canadian seniors participating in the Canadian Study of Health and Aging. Can J Clin Pharmacol 1995;2:167-74.
  58. Whittle J, Wickenheiser L, Venditti LN. Is warfarin underused in the treatment of elderly persons with atrial fibrillation? Arch Intern Med 1997;157:441-5.
  59. Soumerai SB, McLaughlin TJ, Spiegelman D, Hertzmark E, Thibault G, Goldman L. Adverse outcomes of underuse of ß-blockers in elderly survivors of acute myocardial infarction. JAMA 1997;277:115-21.
  60. Colley CA, Lucas LM. Polypharmacy: the cure becomes the disease. J Gen Intern Med 1993;8:278-83.
  61. McLeod PJ, Huang AR, Tamblyn RM, Gayton DC. Defining inappropriate practices in prescribing for elderly people: a national consensus panel. CMAJ 1997;156:385-91 [full text / résumé].
  62. Hanlon J, Weinberger M, Samsa GP, Schmader KE, Uttech KM, Lewis IK, et al. A randomized controlled trial of a clinical pharmacist intervention to improve inappropriate prescribing in elderly outpatients with polypharmacy. Am J Med 1996;100:428-37.
  63. Hanlon JT, Schmader KE, Samsa GP, Weinberger M, Uttech KM, Lewis IK, et al. A method for assessing drug therapy appropriateness. J Clin Epidemiol 1992;45:1045-51.
  64. Newton P, Levinson W, Maslin D. The Geriatric Medication Algorithm: a pilot study. J Gen Intern Med 1994;9:164-7.
  65. Approaches to enhancing the quality of drug therapy. A joint statement by the CMA and the Canadian Pharmaceutical Association. CMAJ 1996;155:784A-784C [full text / text complet].
  66. Torrible SJ, Hogan DB. Medication use and rural seniors: Who really knows what they are taking? Can Fam Physician 1997;43:893-8.
  67. Seniors' drug costs continue to rise. Drug Use Elderly Q 1996;April:3-4.

Comments Send a letter to the editor responding to this article
Envoyez une lettre à la rédaction au sujet de cet article

| CMAJ October 15, 1997 (vol 157, no 8) / JAMC le 15 octobre 1997 (vol 157, no 8) |