Cochrane for Clinicians
Putting Evidence into Practice
Improving Adherence to Treatment for Hypertension
The Cochrane Abstract below is a summary of a review from the Cochrane Library. It is accompanied by an interpretation that will help clinicians put evidence into practice. Frank J. Domino, M.D., presents a clinical scenario and question based on the Cochrane Abstract, along with the evidence-based answer and a full critique of the abstract.
This clinical content conforms
to AAFP criteria for evidence-based continuing medical education (EB CME). EB
CME is clinical content presented with practice recommendations supported by
evidence that has been systematically reviewed by an AAFP-approved source. The
practice recommendations in this activity are available online at
http://www.cochrane.org/cochrane/revabstr/AB004804.htm.
Clinical Scenario
M.L. is a 58-year-old man with poorly controlled hypertension; he has been prescribed 100 mg of metoprolol twice daily. He says he is so tired when he gets home at night that he usually goes to bed without taking the second dose of his medication.
Clinical Question
What methods are effective at improving adherence to treatment in patients with hypertension?
Cochrane abstract
Background. Lack of adherence to blood pressure-lowering medication is a major reason for poor control of hypertension worldwide. Interventions to improve adherence to antihypertensive medication have been evaluated in randomized trials, but it is unclear which interventions are effective.
Objectives. To determine the effectiveness of interventions aimed at increasing adherence to blood pressure-lowering medication in adults.
Search Strategy. The authors1 performed an all-language search of all articles in the Cochrane Controlled Trials Register, MEDLINE, EMBASE, and CINAHL in April 2002.
Selection Criteria. The authors selected randomized clinical trials (RCTs) of interventions to increase adherence to blood pressure-lowering medication in adults with essential hypertension, with adherence to medication and blood pressure control as outcomes.
Data Collection and Analysis. Two authors extracted data independently and in duplicate and assessed each study according to the criteria outlined by the Cochrane Collaboration Handbook.
Primary Results. The authors included 38 studies testing 58 different interventions and containing data on 15,519 patients. The studies were conducted in nine countries between 1975 and 2000. The duration of follow-up ranged from two to 60 months. Due to heterogeneity between studies in terms of interventions and the methods used to measure adherence, results were not pooled. Simplifying dosing regimens increased adherence in seven out of nine studies (relative increase in adherence, 8 to 19.6 percent). Motivational strategies were successful in 10 of 24 studies, with generally small increases in adherence, up to 23 percent. Complex interventions involving more than one technique increased adherence in eight out of 18 studies, ranging from 5 to 41 percent. Patient education alone seemed largely unsuccessful.
Reviewers' Conclusions. Reducing the number of daily doses appears to be effective in increasing adherence to blood pressure-lowering medication and should be tried as a first-line strategy, although there is less evidence of an effect on blood pressure reduction. Some motivational strategies and complex interventions appear promising, but more evidence is needed from RCTs.
These summaries have been
derived from Cochrane reviews published in the Cochrane Database of Systematic
Reviews in the Cochrane Library. Their content has, as far as possible, been
checked with the authors of the original reviews, but the summaries should not
be regarded as an official product of the Cochrane Collaboration; minor editing
changes have been made to the text (www.cochrane.org).
Evidence-Based Answer
The most effective strategy to improve patient compliance with antihypertensive medication is to simplify the dosing regimen. There is more limited evidence to support a variety of motivational strategies. Patient education alone is ineffective.
|
Once-Daily Blood Pressure Medications Without Special Dosing Requirements |
|
|
Angiotensin-converting enzyme inhibitors Benazepril Enalapril Fosinopril Lisinopril Quinapril Ramipril Trandolapril Angiotensin II antagonists Candesartan Irbesartan Losartan Olmesartan Telmisartan Valsartan Beta-adrenergic antagonists Atenolol Betaxolol Carteolol Metoprolol Nadolol Penbutolol |
Calcium channel blockers Dihydropyridines Amlopidine Felodipine Nifedipine Nondihydropyridines Diltiazem Verapimil Thiazides Bendropflumethiazide Chlorothiazide Chlorthalidone Hydrochlorothiazide Indapamide Methylclthiazide Metolazone Trichlormethiazide |
Practice Pointers
Treatment of high blood pressure with medication can reduce the risk of stroke by 31 to 45 percent, and myocardial infarction by 8 to 23 percent.2,3 Despite this benefit, control of hypertension in the ambulatory setting is suboptimal. Adherence to treatment regimens for high blood pressure is estimated to be between 50 and 70 percent.4
Simplification of treatment is the most effective intervention. Medications that can be taken once a day (see accompanying table) are preferred, as long as the increased cost of a once-daily formulation does not pose a barrier to adherence. If the patient is taking other medications, consider recommending that all be taken at the same time of day. Medications with special requirements (e.g., bedtime dosing, avoiding meals) should be used only if alternatives are unavailable or atypical circumstances exist. It is important to note that while dosing simplification improved adherence in seven out of nine studies, only one study showed an improvement in adherence and in systolic blood pressure by changing from twice-daily to once-daily dosing. No study found an improvement in diastolic blood pressure with improved adherence.
|
Once-Daily Blood Pressure Medications Without Special Dosing Requirements |
|
|
Angiotensin-converting enzyme inhibitors Benazepril Enalapril Fosinopril Lisinopril Quinapril Ramipril Trandolapril Angiotensin II antagonists Candesartan Irbesartan Losartan Olmesartan Telmisartan Valsartan Beta-adrenergic antagonists Atenolol Betaxolol Carteolol Metoprolol Nadolol Penbutolol |
Calcium channel blockers Dihydropyridines Amlopidine Felodipine Nifedipine Nondihydropyridines Diltiazem Verapimil Thiazides Bendropflumethiazide Chlorothiazide Chlorthalidone Hydrochlorothiazide Indapamide Methylclthiazide Metolazone Trichlormethiazide |
Patient-centered motivational counseling should identify barriers to medication compliance and include patients in prescribing decisions. Successful motivational strategies include daily reminder charts, training in self-determination, packaging medications in combination, social and family support, telephone calls from nurses, electronic medication aid caps, and telephone-linked computer counseling.
The Author
Frank J. Domino, M.D., is associate professor of family medicine and community health at the University of Massachusetts Medical School, Worcester.
Address correspondence to Frank J. Domino, M.D., University of Massachusetts Medical School, Family Medicine & Community Health, 55 Lake Ave. North, Worcester, MA 01655 (e-mail: dominof@ummhc.org). Reprints are not available from the author.
REFERENCES
1. Schroeder K, Fahey T, Ebrahim S. Interventions for improving adherence to treatment in patients with high blood pressure in ambulatory settings. Cochrane Database Syst Rev 2004;(3):CD004804.
2. Neal B, MacMahon S, Chapman N. Effects of ACE inhibitors, calcium antagonists, and other blood-pressure-lowering drugs: results of prospectively designed overviews of randomised trials. Blood Pressure Lowering Treatment Trialists' Collaboration. Lancet 2000;356:1955-64.
3. Psaty BM, Koepsell TD, Wagner EH, LoGerfo JP, Inui TS. The relative risk of incident coronary heart disease associated with recently stopping the use of beta-blockers. JAMA 1990;263:1653-7.
4. Caro JJ, Speckman JL, Salas M, Raggio G, Jackson JD. Effect of initial drug choice on persistence with antihypertensive therapy: the importance of actual practice data. CMAJ 1990;160:41-6.
Cochrane Briefs
Treating GER in Children Younger Than Two Years
Clinical Question
Do thickened feeds, elevating the head of the crib, and metoclopramide therapy improve the symptoms of gastroesophageal reflux (GER) in normally developing children younger than two years?
Evidence-Based Answer
Thickened feeds and metoclopramide reduce symptoms of GER in normally developing infants. However, elevating the head of the crib appears to have no effect.
Practice Pointers
Although virtually all infants regurgitate, or "spit up,” about 3 percent of normally developing infants have clinically significant GER. If an infant has poor weight gain, excessive crying, irritability, disturbed sleep, respiratory problems, or signs of obstruction, diagnostic testing or referral is indicated. Referral also is indicated for patients whose symptoms persist beyond 24 months of age. Common first-line treatments are reassuring parents, elevating the head of the baby's crib, trying a hypoallergenic formula, and thickening feeds with rice cereal or a rice- or carob-based thickener. Medication sometimes is used for refractory or complicated cases.1
To determine whether common practice is supported by the literature, Craig and colleagues systematically reviewed randomized trials involving thickened feeds, positioning, or metoclopramide to reduce the symptoms of reflux in children younger than two years with no apparent developmental delay. They found 20 trials with a total of 771 infants; eight trials studied thickened feeds, five positioning, and seven metoclopramide. However, not all studies in each group could be compared because of the differences in measured outcomes. Standardized mean differences (SMDs) and weighted mean differences (WMDs) were reported; more negative numbers indicate a greater reduction.
Neither elevating the head of the bed nor putting the patient in prone position (five studies) was found to be effective in reducing reflux. However, thickening feeds (two studies with 48 patients in total) significantly reduced the regurgitation severity score (SMD: -0.94) and frequency of vomiting (SMD: -0.91). Thickened feeds were not found to reduce the reflux index (WMD: 0.48), and may increase the chances of cough and diarrhea. Metoclopramide (two studies totalling 101 patients) significantly reduced daily symptoms (SMD: -0.73), and the reflux index (WMD: -2.80). Side effects such as irritability or drowsiness may occur, although results were heterogeneous. Results of studies that could not be combined generally were similar to those reported above.
CLARISSA KRIPKE, M.D.
Craig WR, et al. Metoclopramide, thickened feedings, and positioning for gastro-oesophageal reflux in children under two years. Cochrane Database Syst Rev 2004;(3):CD003502.
REFERENCE
1. Rudolph CD, Mazur LJ, Liptak GS, Baker RD, Boyle JT, Colletti RB, et al. Guidelines for evaluation and treatment of gastroesophageal reflux in infants and children: recommendations of the North American Society for Pediatric Gastroenterology and Nutrition. J Pediatr Gastroenterol Nutr 2001;32(suppl 2):S1-31.
Umbilical Cord Clamping in Preterm Infants
Clinical Question
What is the optimal time to clamp the umbilical cord for infants born at less than 37 weeks' gestation?
Evidence-Based Answer
In preterm infants, clamping the umbilical cord between 30 seconds and two minutes after delivery is associated with lower rates of blood transfusion and intraventricular hemorrhage.
Practice Pointers
Many patients request delayed umbilical cord clamping in their birth plans. Delayed cord clamping allows continued perfusion while the baby transitions to newborn circulation. However, when an infant is high risk, physicians frequently clamp and cut the cord early to allow the neonatal resuscitation team quicker access.
Rabe and colleagues reviewed the literature to determine the impact of early and delayed cord clamping on outcomes in preterm infants. They found seven randomized controlled trials that compared early and delayed cord clamping in a total of 297 preterm infants. Delaying cord clamping up to two minutes was associated with a higher hematocrit at four hours of life than early clamping (weighted mean difference: 5.31 g), fewer blood transfusions for anemia (25 versus 52 percent) and hypotension (20 versus 50 percent), and fewer intraventricular hemorrhages (17 versus 26 percent). All of these differences were significant. No statistically significant differences in respiratory outcomes were reported. However, the numbers of patients in the studies that reported this outcome were small.
Results for term infants also appear to be favorable. Van Rheenen and colleagues1 reviewed the literature on delayed cord clamping in term infants, and found that delaying cord clamping reduced anemia at two to three months of age. The results showed a 12 percent increased risk of hyperbilirubinemia, but in no study was this condition reported to require treatment.
An alternative to early cord clamping for resuscitation access is to deliver the baby without breaking down the bed. This allows resuscitation personnel and equipment to be brought to the bedside before the cord is clamped.
Rabe H, et al. Early versus delayed umbilical cord clamping in preterm infants. Cochrane Database Syst Rev 2004;(3):CD003248.
REFERENCE
1. van Rheenen P, Brabin BJ. Late umbilical cord-clamping as an intervention for reducing iron deficiency anaemia in term infants in developing and industrialised countries: a systematic review. Ann Trop Paediatr 2004;24:3-16.
| Copyright © 2005 by the American
Academy of Family Physicians. |
MEDLINE:
• Citation
More in AFP:
• Cochrane for Clinicians: Putting Evidence into Practice (93)
• Antihypertensive Agents (19)
• Hypertension (47)
• Patient Compliance (8)