Which older people decline participation in a primary care trial of physical activity and why: insights from a mixed methods approach

We aimed to elucidate factors influencing participation in a primary care PA trial in older adults by: 1) comparing demographic details of all those invited to participate; 2) comparing self-reported socio-demographic characteristics, health status and PA levels of participants with those of non-participants who completed a survey; and 3) exploring in interviews a sample of non-participants’ perceived barriers to participation.

A two-phase mixed-methods sequential explanatory design was used. Phase one involved collection of quantitative data using general practice records and a questionnaire survey. Phase two involved semi-structured interviews with a sample of trial non-participants. The rationale for this approach was to explain quantitative results by exploring non-participants’ views in more breadth and depth [14].

Three general practices in Oxfordshire and Berkshire, United Kingdom. Practices were selected that had the following: a list size >10,000 patients or >1400 patients aged 60–74 years; a practice nurse interested in carrying out the physical activity interventions; and the availability of a room for the research assistant.

Patients aged 60–74 years registered at participating practices were invited to take part in the trial if they could walk outside and had no contraindications to increasing PA. Computerised primary care records were screened by Read codes for exclusions and random samples of households were selected. (If there were 2 members of a couple living at the same address who were both potentially eligible this was a ‘double’ household; if there was only one person potentially eligible this was a ‘single’ household). General practitioners (family physicians) then scrutinised these for further exclusions, before posting study invitations (Figure 1). The invitation included trial information and a response sheet with the options of i) trial participation, ii) completing a survey or iii) no further contact. There were 298 trial participants and 690 non participants, of whom 183 completed a questionnaire.

This was provided by NRES Committee Oxford C 11/H0606/2.

The interviewer (AR) was a research assistant unknown to the interviewees. The semi-structured interview schedule was developed collaboratively and iteratively between AR, CV, AW and TH.

The interviews were transcribed verbatim. Transcripts were subjected to an initial analysis stage ‘data reduction’ [16] involving selecting and transforming the data as meanings and insights from the words of interviewees. AR uploaded the data onto QSR Nvivo (V9.0, Scientific Software) and read each transcript several times. This enabled identification of patterns both within and across transcripts with the aim of ensuring that recurrent codes were subject to closer scrutiny; alternative interpretations were explored, as advised in the qualitative analysis coding manual [16]. The initial thematic framework was discussed during monthly face-to-face meetings with co-researchers who had read and coded the 15 transcripts independently, discrepancies were resolved and additional codes refined until consensus was reached. Nvivo keyword searches were used to identify overlooked material.

Trial recruitment was 30% (298/988). Participants were slightly but not significantly younger than non-participants (Table 1.) They were more likely to be female (p = 0.04) but being invited as a couple did not affect response. More participants lived in the most affluent quintile of Index of Multiple Deprivation, 73%, compared with 62% of non-participants (p < 0.001). However, the overall sample from the three practices was relatively affluent, with 65% (643/988) living in the least deprived quintile of deprivation, compared to 20% nationally [15].

Trial participants and non-participants completing the survey did not differ in marital or retirement status or whether they had been invited to take part as a couple. Smoking status and ethnicity showed no differences, but as only 6% were smokers and only about 1% were non-white, these comparisons lacked statistical power. However, participants were more likely to have an occupational pension, adjusted OR 2.06 (1.35-3.13). Trial participation was positively associated with having a limiting long-standing illness, adjusted OR 1.72 (1.05-2.79) and having one or more chronic diseases, adjusted OR 1.68 (1.14-2.47). Participants tended to be overweight or obese adjusted OR 1.40 (0.93-2.09) and in pain adjusted OR 1.43 (0.96-2.12), but neither difference was statistically significant. General health, use of a walking aid, falls, number of medications, mobility or self-care problems, anxiety or depression, showed no association with participation. Participation was significantly associated with lower self-reported PA: slower walking pace, adjusted OR 0.56 (0.37-0.84) and lower activity levels, adjusted OR 0.55 (0.33-0.93). The main reasons given on the survey for non-participation were: already physically active (67%); time constraints (44%); lack of interest (25%).

Amongst trial non-participants, the 77 who agreed to be approached for an interview were compared to those who did not (106). There were no statistically significant differences in age group 32% (24/77) versus 39% (41/106) age 70–75 (p = 0.37); gender 53% (41/77) versus 47% (50/106) male (p = 0.42); invited as a couple 51% (39/77) versus 52% (55/106) (p = 0.87); BMI 54% (37/69) versus 64% (59/92) overweight or obese (p = 0.18) or IMD score 71% (55/77) versus 73% (77/106) in least deprived quintile (p = 0.59). There was a significant difference in self-reported PA, with those who agreed to be interviewed more likely to answer the question and to self-report higher PA levels, 53% (40/76) versus 35% (31/89) categorised as “active” on GPPAQ (p = 0.021). Table 3 summarises key themes from the 15 interviews conducted. Barriers to trial participation included reluctance to walk either alone, in the evening, or in bad weather, linked to a fear of falling in wet weather and reduced confidence in pursuing PA. Poor physical and psychological health, symptoms of medical conditions, particularly arthritis and joint pain, psychological health concerns such as depression and low energy levels reduced the desire to exercise, as did a fear of “overdoing things”, with the view that PA might cause “more harm than good”. The predominant explanation for non-participation was the perception that they were already doing enough PA; they were aware of the health benefits of keeping active and believed that the trial would provide minimal benefit. The commitment required to participate was mentioned by those who expressed the desire to take on fewer commitments, those reluctant to change existing routines and where interviewee’s priorities (work, family and recreation) were given priority over pursuit of PA. Some expressed concerns about lengthy trial duration and uncomfortable trial equipment.

In terms of positive trial features, interviewees supported the focus on walking over other PA for their age group and the involvement of general practice (family practice).

The study achieved a good recruitment rate for a primary care PA trial [7, 8, 19, 20], in a relatively affluent white population. Within this context, participants were more likely to come from affluent postcodes and be female, but being invited as an individual or as part of a couple did not affect response. Non-participants completing a survey were less likely than participants to report health problems and more likely to report being physically active, suggesting appropriate trial self-selection. This suggests that primary care recruitment could encourage those with more illnesses and primary care contact to join PA trials and fits with recommendations to improve recruitment of older people into research, particularly clinical trials [21]. The qualitative results supported the survey finding that some non-participants thought they were already sufficiently active, whilst physical symptoms, depression, time restraints, trial equipment and duration were important barriers to participation for others.

The main strength was the mixed methods approach of the study, with the ability to examine routinely collected demographic data on all those invited to participate, supported by more detailed data on health and PA levels of non-participants completing a survey and interview data from a purposively selected sample. It is difficult to obtain more than demographic information on non-participants [6, 9, 10], so any information is valuable from a public health perspective for exploring reasons why older people do not want to participate in PA interventions. Approximately 50% of patients either participated in the trial or the survey, confirming the value of this work. However, we cannot assume that reasons given by survey responders or by the small group of interviewees, apply to all trial non-participants; indeed whilst those agreeing to be interviewed were similar on most measures to those not agreeing, they reported higher PA levels. We were limited in the socio-economic measures assessed: only postcode and therefore IMD score [15] for all non-participants; only receipt of an occupational pension for those non-participants responding to the questionnaire. A further limitation was that the BMI of non-participants was calculated from self-reported height and weight, whereas these were objectively measured in participants. This could have led to under-reporting of BMI in non-participants, inflating the difference between participants and non-participants.

Our recruitment rate of 30% compares well to other primary care physical activity interventions in this age group: 6% [7], 14% [20], 17% [19], 35% [8], reflecting the relatively affluent setting. Participants were more likely than non-participants to report having a limiting longstanding illness, and one or more chronic diseases (and a tendency, although not statistically significant, to suffer pain and to be overweight or obese) supporting work which found that those with a greater disease history and primary care contact were more likely to participate in primary care PA studies [9, 12] and refuting a ‘healthy volunteer effect’ [11]. Participants reported being less active and having lower walking speeds than the non-participants surveyed, consistent with their poorer physical health. This contrasts with our previous work where participants reported more PA [9]. However, that was an observational study, objectively measuring usual PA, and may have attracted those interested in PA. The current study required commitment to increase PA levels over 3–12 months [13], so those who felt they were sufficiently active may have been less likely to participate.

The interviews provided insight into perceived barriers to PA trial participation. Already considering themselves sufficiently active was a common reason for non-participation, though this may be due to higher self-reported PA levels in those who agreed to be interviewed and an overestimation of what they actually did [6, 22]. However, several interviewees confirmed that they were not physically active. Despite reporting an understanding of health benefits, their health concerns impeded them from exercising. Current poor health, including joint pain, as well as psychological factors such as depression, fear of falling and low energy were mentioned as reasons for not participating in PA, consistent with other work [6]. These findings have implications for primary care-based trials, suggesting that patients need tailored information concerning symptom management, highlighting safety and joint protection and evidence that PA can be beneficial and may alleviate painful joints [23]. Furthermore, there is a need to emphasise mental health benefits, so that a perceived barrier to exercise may become a potential benefit [24].

In common with previous studies [25, 26], lack of time was a common reason for non-participation. This was linked to work and recreational commitments, in addition to ‘slowing down’ in retirement, taking things at a leisurely pace. Although interviewees acknowledged that no programme could accommodate everyone, juggling competing responsibilities such as work and family was a barrier. Similar to previous findings [27], some interviewees cited long working hours and related fatigue as reasons for finding exercise difficult to fit in. The majority talked about the importance of maintaining a balance between work and leisure, and the possible disruption caused by increased PA. A change in emphasis is needed to ensure that older people understand the importance of exercising, and recognise that exercise can be pleasurable. These qualitative findings illustrate the importance of tailoring PA to match individual interests when designing interventions [28]. Whilst this was an important feature of our intervention, it could have been emphasised more in recruitment materials, pre-empting potential barriers.

A reluctance to go out in the evening and to go out alone prevented some from participating, as highlighted previously [6]. Trial invitations were staggered over a year, and those approached over winter were discouraged by seasonal factors and fear of falling. This highlights the importance of safety and confidence in PA and the need to address self-efficacy, which is positively related to PA engagement by older adults [29]. Organised group exercise within PA interventions may enable participants to meet others of a similar fitness level and may reduce safety concerns [30]. However, interviewees in our study supported walking as the best choice of activity for this age group and primary care as an appropriate venue for the intervention, with practice nurse support, and this model has been successful previously [31]. Outdoor walking interventions in primary care could usefully recruit in the spring or summer, building new habits before the weather deteriorates.