Baseline and Follow‐Up Characteristics of Participants and Nonparticipants in a Randomized Clinical Trial of Multifactorial Fall Prevention in Denmark

Abstract

Nonresponding nonparticipants of a trial of multifactorial fall prevention differed significantly from participants in terms of socioeconomic and morbidity variables and were more likely to be hospitalized or die during 6 months of follow-up. Because of the differences between the two populations, it is questionable whether results from this randomized trial can be generalized to people potentially eligible for participation.

Rückenschmerz und Sozialschicht bei Berufstätigen

“…Darüber hinaus sind Berufstätige aus bildungsschwachen Haushalten unterrepräsentiert, was durch die verwendeten statistischen Gewichte zumindest teilweise ausgeglichen werden kann. Es ist wahrscheinlich, dass gezielt am unteren und oberen Rand des Einkommensspektrums verstärkt Antwortverweigerungen auftraten [45,47]. Angesichts des teilweise starken Zusammenhangs zwischen Bildung und Rückenschmerzoutcome ist es unwahrscheinlich, dass diese Auswahlprozesse die grundlegenden Schlussfolgerungen beeinflusst haben.…”

Baseline participation in a health examination survey of the population 65 years and older: who is missed and why?

“…In recent decades, population-based health surveys have been facing decreasing participation rates [ 1 ]. Especially health studies of the older population are plagued by high non-response rates [e.g., 2 – 4 ]. This could compromise the validity of study results.…”

Designing clinical trials in older people

“…Reporting of the characteristics of responding and nonresponding nonparticipants will also assist in assessing the generalisability and interpretation of the study results, as those that do not respond are more likely to have significant co-morbidities or be hospitalised, and may be the group most likely to benefit from the investigated intervention. If there is significant non-response it may be that the results cannot be generalised even to others that meet eligibility criteria [7].…”

“…Other barriers include the extra time and resources needed to recruit older patients, and the extra support they may require to ensure retention. Even when older people are included in studies, selection bias occurs such that those who are healthier and with higher economic status tend to participate, casting doubt on the general applicability of the results [7]. These problems affect all branches of elderly medicine -from falls prevention to oncology.…”

“…Investigators should consider whether measures need to be put in place to counteract the difficulties associated with nonresponse or nonparticipation of patients who fulfil eligibility criteria, such as adopting alternative randomisation methods (e.g. cluster randomisation) [7]. When selecting outcome measures, it is important to ensure that as far as achievable, scales and assessment tools have been validated for use in the target population, for example self-completion scales developed in a younger population may have a form of wording with which a more elderly participant may not identify [8].…”