Canadian Task Force on Preventive Health Care

Structured Abstract

Please note: In 2003, the CTF updated its Grades of Recommendations to include an "I Recommendation" for situations where insufficient evidence exists to allow a recommendation to be made.  (Formerly, these situations were captured under a "C Recommendation".)  This change is not retroactive, and all "C Recommendations" made prior to 2003 have not been reevaluated in light of the new "I" recommendation grade.  For a discussion of these recommendation grades, please link to the 2003 article in the Canadian Medical Association Journal here.

Hypertension in the Elderly: Case-Finding and Treatment to Prevent Vascular Disease

Prepared by Christopher Patterson, MD, FRCPC, Professor and Head, Division of Geriatric Medicine, McMaster University, Hamilton, Ontario, and Alexander G. Logan, MD, FRCPC, Professor of Medicine, University of Toronto

These recommendations were finalized by the Task Force in January 1994

Contents

Objective

To make recommendations about case-finding and treatment of hypertension in elderly persons in Canada. This updates a 1984 Task Force report.

Burden of Suffering

Systolic hypertension is defined as an average blood pressure (BP) >160 mmHg measured on multiple readings on several occasions by sphygmomanometer cuff.  Diastolic hypertension is an average diastolic BP (Korotkoff V) ?90 mmHg.  The prevalence of isolated systolic hypertension (systolic BP >160 mmHg, diastolic BP< 90 mmHg) on two occasions) was about 10% of white Americans over 65 years of age, in the screening phase of the Systolic Hypertension in the Elderly Program (SHEP) study.  The prevalence rose to 20% in those over age 80 years.  The prevalence of diastolic hypertension (diastolic BP >90 mmHg on two occasions) was found to be about 11% of white Americans and over 26% of black Americans in the screening phase of the Hypertension Detection and Follow-up Study.  Other estimates based upon single measurements of BP have estimated prevalence considerably higher than these figures.

 Epidemiological studies, for example those arising from Framingham, Massachusetts have determined that the risks of death and morbid events relate independently to both systolic and diastolic hypertension.  The risks of stroke and of cardiovascular diseases rise with age, given the same levels of BP.  Thus, the rate of morbid events is age-dependent, for both men and women.  In general, rates for men are higher than for women of the same age with similar levels of BP.  Moderate degrees of hypertension are usually asymptomatic in all age groups.

Options

The only case-finding measure was the mercury sphygmomanometer. Treatment focused on drug therapy using diuretics, beta-blockers, methyldopa and reserpine.

Outcomes

Mortality (all-cause, cardiovascular/cardiac, cerebral vascular), morbid cardiovascular events (including myocardial infarction, left ventricular failure) and stroke (all, fatal).

Evidence

MEDLINE was searched to 1993 using the MeSH headings "hypertension", "aged", "aged over 80" and publication type "clinical trial". Other data sources were recent meta-analyses, review articles and input from experts. Study results were synthesized in table or graphic format only.

Recommendations were graded as:
A
 Good evidence to support the recommendation that the condition be specifically considered in a PHE. 
B
 Fair evidence to support the recommendation that the condition be specifically considered in a PHE. 
C
 Poor evidence regarding inclusion or exclusion of the condition in a PHE, but recommendations may be made on other grounds. 
D
 Fair evidence to support the recommendation that the condition be specifically excluded from consideration in a PHE. 
E
 Good evidence to support the recommendation that the condition be specifically excluded from consideration in a PHE. 
Quality of evidence was rated according to 5 levels:
I
 Evidence from at least 1 properly randomized controlled trial (RCT). 
II-1
 Evidence from well-designed controlled trials without randomization. 
II-2
 Evidence from well-designed cohort or case-control analytic studies, preferably from more than 1 centre or research group. 
II-3
 Evidence from comparisons between times or places with or without the intervention. Dramatic results in uncontrolled experiments could also be included here. 
III
 Opinions of respected authorities, based on clinical experience, descriptive studies or reports of expert committees. 

Values

The 13-member Task Force of experts in family medicine, geriatric medicine, pediatrics, psychiatry and epidemiology used an evidence-based method for evaluating the effectiveness of preventive health care interventions. Recommendations were not based on cost-effectiveness of options. Patient preferences were not discussed.

Background papers providing critical appraisal of the evidence and tentative recommendations prepared by the chapter author were pre-circulated to the members. Evidence for this topic was presented and deliberated upon in 1- to 2-day meetings, 2 to 3 times per year from January 1993 to June 1993. Consensus was reached on final recommendations.

Benefits, Harms, and Costs

4 RCTs confirm the benefits of drug therapy for older persons with systolic blood pressure (BP) > 160 mmHg and diastolic BP >90 mmHg. Major results are summarized below. To allow for comparisons, relative risks have been converted to relative risk reductions1. Converted results are indicated by { }.
 
 
Study Design and Patients
All-cause Mortality
Cardiovascular Mortality
Cardiovascular Events
Strokes
European Working Party on High Blood Pressure in the Elderly Trial

Randomized, double-blind treatment with diuretics, then methyldopa 

840 clinic patients >60 yrs with systolic BP 160 - 239 mmHg + diastolic BP 90 - 119 mmHg
NS
RRR 27%
p = 0.04
NNT52 = 23
RRR 60% 
p = 0.06
NNT5 = 37 (nonfatal cerebral vascular event)
  
Systolic Hypertension in the Elderly Program

Randomized, double-blind treatment with diuretics, then beta-blockers or reserpine

4000 persons >60 years with systolic BP 160 - 219 mmHg + diastolic BP<90 mmHg + no history of major cardiovascular disease
NS
  
RRR 33% 
CI3 4% - 53%
NNT5 = 90 (MIs)
RRR 37%
CI 18% - 51%
p = 0.0003
NNT5 = 40
Swedish Trial in Older Patients with Hypertension

Random allocation to 4 drugs (diuretic combination and 3 beta-blockers)

Men & women 70 - 84 yrs with systolic BP 180 - 230 mmHg + diastolic BP >90 mmHg or diastolic BP 105 - 120 + no myocardial infarction (MI) or stroke within 1 yr, or angina requiring more than glyceryl trinitrate.
{RRR 43%}
{CI 13% - 63%}
    
{RRR 47%}
{CI 14% - 67%}
NNT5 = 14 
Medical Research Council trial

Placebo-controlled, double-blind treatment with diuretics or beta blockers

Men & women 65 - 74 yrs with systolic BP 160 - 209 mmHg + diastolic BP £ 114mmHg + no treatment for hypertension, MI or stroke within 3 mos, or other significant diseases.

    
RRR 17%
CI 2% - 29%
p=0.04
RRR 25%
CI 3%- 42%
p=0.04
1 Relative risk reduction = 1 - relative risk
2 Number needed to treat over 5 years
3 95% confidence interval

Neither adverse effects nor costs of treatment were discussed.

Recommendations

Recommendation grade [A, B, C, D, E]  and level of evidence [I, II-1, II-2, II-3, III] are indicated after each recommendation. Citations in support of individual recommendations are identified in the guideline text.

Validation

This report was externally peer-reviewed. The 1989 U.S. Preventive Services Task Force recommended routine BP measurement in persons over age 3 years.

Sponsors

The Canadian Task Force on the Periodic Health Examination developed this guideline with funding from Health Canada.

Documents

Source Other


Link to Full Text of this review

Link to Summary Table of Recommendations of this review

Link to Selected References list of this review

Top of Page

Home PageCTFPHC Home Page

Copyright © 1997 Canadian Task Force on Preventive Health Care
For any technical issues please contact: webmaster@ctfphc.org
Last modified: June 10, 1998.