Primary and Secondary Prevention Interventions for Cognitive Decline
Total Page:16
File Type:pdf, Size:1020Kb
2016 Primary and secondary prevention interventions for cognitive decline and dementia Overview of reviews Published by The Norwegian Institute of Public Health Section for evidence summaries in the Knowledge Centre Title Primary and secondary prevention interventions for cognitive decline and dementia Norwegian title Primær‐ og sekundærforebyggende tiltak for kognitiv svikt og demens Responsible Camilla Stoltenberg, direktør Authors Gerd M Flodgren, project leader, researcher, the Knowledge Centre Rigmor C Berg, Head of Unit, for Social Welfare Research at the Knowledge Centre ISBN 978‐82‐8082‐745‐6 Projectnumber 798 Type of publication Overview of reviews No of pages 69 (110 inklusiv vedlegg) Client Nasjonalforeningen for folkehelsen MeSH terms Alzheimer’s disease, dementia, cognition, cognitive impairment, cognitive disorders, memory complaints, primary prevention, secondary prevention Citation Flodgren GM, Berg RC. Primary and secondary prevention interventions for cognitive decline and dementia. [Primær‐ og sekundærforebyggende tiltak for kognitiv svikt og demens] Rapport −2016. Oslo: Folkehelseinstituttet, 2016. 2 Table of contents Table of contents TABLE OF CONTENTS 3 KEY MESSAGES 5 EXECUTIVE SUMMARY 6 Background 6 Objectives 6 Methods 6 Results 6 Discussion 8 Conclusions 8 HOVEDFUNN (NORSK) 9 SAMMENDRAG (NORSK) 10 Bakgrunn 10 Problemstillinger 10 Metoder 10 Resultat 10 Diskusjon 12 Konklusjon 12 PREFACE 13 OBJECTIVES 15 BACKGROUND 16 Description of the condition 16 How the interventions may work 18 Why is it important to do this overview of reviews? 21 METHODS 22 Objectives 22 Inclusion criteria 22 Exclusion criteria 23 Literature search 23 Selection of reviews 24 Data extraction 24 Data synthesis 25 Grading of the evidence 25 3 Table of contents Ethics 26 RESULTS 27 Description of included reviews 27 Primary prevention interventions 31 Secondary prevention interventions 37 Certainty of the evidence 40 Effects of interventions 41 Ethics 50 DISCUSSION 52 Main results 52 Certainty of the evidence 52 Strengths and weaknesses 53 Potential biases in the overview process 54 Overall completeness and applicability of the evidence 54 Agreements or disagreements with other overviews of reviews 57 Applications for practice 57 Need for further research 57 CONCLUSION 59 REFERENCES 60 APPENDICES 71 1 Glossary 71 2 Search strategy 77 3 Excluded reviews and reasons for exclusion 88 4 Assessment of methodological quality 90 5 Ongoing reviews 92 6 Description of included reviews 93 7 GRADE evidence profiles 97 4 Table of contents Key messages Dementia is a syndrome characterised by deterioration in memory, Title: thinking, behaviour, and the ability to perform everyday activities, Primary and secondary which ultimately may lead to total dependence and death. Since the prevention interventions for cognitive decline and dementia world’s population is steadily growing older, the number of people with ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ dementia is also increasing. It is therefore of utmost importance to Type of publication: identify effective strategies to prevent or delay its onset. Overview of reviews ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ The key findings of this overview of reviews are based on evidence Doesn’t answer everything: from eight systematic reviews. The results for the single interventions No interventions targeting people with dementia. targeting cognitively healthy people suggest that compared to control: No health economic Antihypertensive drugs may lead to a slight decrease in incidence of evaluation. dementia in people with hypertension (low certainty of evidence). ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Statin therapy probably leads to little or no difference on incidence Who is responsible for this publication? of dementia in people with, or at risk of, cardiovascular disease The Norwegian Institute of (moderate certainty). Public Health completed this Omega‐3 Fatty Acids (FAs) probably lead to little or no effect on assignment which was com‐ cognitive test scores (moderate to high certainty). missioned by the National Association of Public Health. Computerised cognitive training probably leads to a slight ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ improvement in cognitive test scores directly after the training When were the literature (moderate certainty). searched? Literature searches were Aerobic exercise may lead to little or no effect on cognitive test conducted in January 2016. scores (low certainty). ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ Peer referees: The results for the interventions targeting people with mild cognitive Øyvind Kirkevold, professor impairment suggest that compared to control: Seksjon for sykepleie Avdeling Cholinesterase inhibitors probably lead to a slight decrease in for helse, omsorg og sykepleie, dementia incidence, but to significantly more adverse events Norges Teknisk‐Naturviten‐ skaplige Universitet. (moderate certainty). Vitamin E probably leads to little or no difference in incidence of Veslemøy Egede‐Nissen, førs‐ Alzheimer’s dementia (moderate certainty). telektor, Institutt for sykepleie Omega‐3 FAs probably lead to little or no difference in cognitive og helsefremmende arbeid, Høgskolen i Oslo og Akershus test scores (moderate to high certainty). We did not find any reviews that evaluated the effects of interventions targeting more than one risk factor, and we can therefore not say anything about the combined effects of these interventions. 5 Key messages Executive summary Background Dementia is a chronic syndrome characterised by deterioration in memory, thinking, behaviour, and the ability to perform everyday activities, which often leads to total de‐ pendence and death. The world’s population is steadily growing older, and as dementia is more prevalent in people over 70, and increases with increasing age, the number of people with dementia is also increasing. In 2012, around 71, 000 people in Norway had a dementia diagnosis, which represents 1.6% of the total population. Objectives The aim of this overview of reviews was to answer the following two questions: 1) What is the documented effectiveness of interventions to prevent cognitive decline or incidence of dementia in cognitively healthy people (primary prevention), 2) What is the documented effectiveness of interventions to prevent (further) cognitive decline or progression to dementia in people with mild cognitive impairment (MCI) or other early symptoms or signs of dementia (secondary prevention)? Methods We conducted an overview of reviews in accordance with the Knowledge Centre’s handbook. We searched in eight databases up to February 2016 for reviews evaluating the effects of interventions to prevent or delay cognitive decline or dementia in people with or without MCI. Two people independently screened all titles and abstracts, re‐ viewed full texts, assessed review quality, and graded the certainty of the evidence us‐ ing the GRADE (Grading of Recommendations Assessment, Development and Evalua‐ tion) tool. One author extracted data, and another checked that it was correct. Results We included eight high quality reviews published between 2009 and 2016. Five of the reviews involved primary prevention interventions for cognitively healthy people. Three reviews included secondary prevention interventions for people with MCI or memory complaints. The reviews evaluated the effects of pharmacological therapies (3 reviews), dietary supplements (3 reviews), aerobic training (one review), and cognitive training (one review). The comparator in the latter two was either another active inter‐ vention or no intervention, and placebo in all the others. 6 Executive summary Primary prevention interventions Pharmacological therapies Antihypertensive drugs. We included one review (4 trials; n=15,936) concerned with the effects of antihypertensive drugs on dementia incidence in older people with hyperten‐ sion. The participants were recruited in Europe, North America, China, Australasia and Tunisia. The pooled result (Odds Ratio [OR]: 0.89 [0.74 to 1.07]) indicates that antihy‐ pertensive drugs may lead to a slight decrease in incidence of dementia, as compared to placebo, at 1.8 to 4.5 years follow up. Cholesterol lowering drugs (Statins). We included one review (2 trials; n=26,340) con‐ cerned with the effects of statins on incidence of dementia in cognitively healthy older people with evidence of, or at high risk of, cerebrovascular disease. The studies were conducted in the UK, Ireland, and the Netherlands. The result of one trial (OR: 1.00 [0.61 to 1.65], n=20,536) indicates that statin therapy may lead to little or no difference in incidence of dementia, as compared to placebo. The other trial (n= 5,804) reported no difference in cognitive test scores between groups at mean 3.2 years follow up. Dietary supplements Omega‐3 Fatty Acids (FAs). We included one review (3 trials; n= 4,080) which evaluated the effects of Omega‐3 FAs on cognitive decline in cognitively healthy participants. The pooled results (Standardised Mean Difference [SMD] [4 tests]: 0.06 higher to 0.04 lower scores; Mean Difference [MD] [2 tests]: 0.12 higher to 0.07 lower scores) suggest that Omega‐3 FA supplementation probably leads to little or no difference in overall cognitive function, as compared to placebo, at 6 to 40 months follow up. Aerobic exercise We included one review (12 trials; n= 754) which evaluated the effects of supervised aerobic exercise on cognitive function in cognitively healthy older people. The studies were conducted in the USA, Canada and France. The pooled