Essay: Short QUestionnaire to ASsess Health-enhancing physical activity (SQUASH)

Background: Regular physical activity has many health-enhancing effects among patients with a physical disability or chronic disease. Accurate assessment of physical activity behaviour is a key factor in ascertaining these health benefits to occur. The adjusted Short QUestionnaire to ASsess Health-enhancing physical activity (adjusted SQUASH) intends to measure this multidimensional construct. This questionnaire has, however, not yet been validated. Objective: The purpose of this study was to determine the concurrent validity of the adjusted SQUASH using the Actiheart activity monitor. Methods: Patients with a physical disability or chronic disease wore the Actiheart activity monitor for one week. Following this period the adjusted SQUASH was completed. The results of the adjusted SQUASH were compared to the data of the Actiheart using a Spearman’s rank correlation and a Bland-Altman analysis. Results: Twenty-one patients (16 women and 5 men, mean age 45 years ± 22) were included for analysis. A significant Spearman’s correlation coefficient was found between the total activity scores of the adjusted SQUASH and the Actiheart, ρ = 0.49. Spearman’s correlation coefficient was 0.38 (p>0.05) for time spent in light activity, 0.02 (p>0.05) for moderate activity and 0.34 (p>0.05) for intensive activity. Bland-Altman analysis showed good agreement between the two measuring methods. Conclusion: The adjusted SQUASH is a fair to good instrument in measuring physical activity behaviour among patients with a physical disability or chronic disease. Future research needs to confirm these results.
Keywords: physical activity, questionnaire, concurrent validity
Introduction
Background
It is a well-known fact that people with a physical disability or chronic disease are less active in daily activities compared to the healthy population (Millan-Calenti et al., 2010). As a result of this physical inactivity they are more at risk of developing a negative spiral deriving from an inactive lifestyle. Obesity, cardiovascular diseases and a reduced quality of life are a few examples of the many health concerns that can be a consequence of this negative spiral (Buffart et al., 2008).
There are norms that state how physically active a person at least should be. As an example, for the healthy Dutch population these norms are set at a recommended minimum of 30 minutes moderate-intensive physical exercise for at least five days a week (Kemper et al., 2004). When these norms are met the benefits of an active lifestyle are substantial and can significantly reduce health concerns (Rosenberg et al., 2011). Adjusted norms are applicable to people with physical disability or chronic disorder. They depend primarily on patient risk (e.g. having an identified weight problem) in combination with type of disease or physical disability (Ampt et al., 2009).
Accurate assessment of physical activity behaviour is a crucial factor in determining if norms are met. Depending on this assessment expert advice can be given to patients to start with counselling like exercise programs (Thompson et al., 2015). If, for example, a decline in physical activity behaviour and endurance seems to be apparent it is important to detect these changes and treat them before it is too late. Therefore, there is a need to measure the pattern of physical activity required for health-enhancing effects to occur (Booth, 2000).
Questionnaires
There are numerous ways to measure physical activity behaviour. The most frequently used measurement tool is a questionnaire (Booth et al., 1996). Questionnaires are low in cost, low in participant burden and are easily administered (Rennie & Wareham, 1998).
A questionnaire developed in the Netherlands designed to measure physical activity behaviour is the Short QUestionnaire to ASsess Health-enhancing physical activity (SQUASH). The SQUASH is based on the compendium of physical activities by Ainsworth, which classifies different activities according to their energy expenditure (Ainsworth et al., 2000). It measures physical activity during commuting, leisure activities, household and at work or school. A strong advantage of the SQUASH is that it only takes five minutes to administer. This questionnaire has proven to be a fairly reliable instrument in measuring physical activity behaviour in healthy adults among the Dutch population (Wendel-Vos et al., 2003). The SQUASH was originally designed for healthy adults but it has also been proven a valid instrument among patients who had a total hip arthoplasty (Wagenmakers et al., 2008) and has been used in studies with osteoarthritis patients (Bossen et al., 2013).
The adjusted SQUASH
Commissioned by the research group Revalidatie, Sport en Bewegen (ReSpAct, www.respact.nl) there was a need to change the original SQUASH into a measurement tool more suitable for persons with a physical disability or chronic disease. This target population has a different perceived intensity of activities compared to the healthy population (Dawes et al., 2005) and is partly wheelchair dependent or uses mobility aid (Hoekstra et al., 2016).
An adjusted version of the SQUASH was developed. Since adjustments have been made to the original SQUASH, it is uncertain if this renewed version still has the same validity as shown in the previous study by Wendel-Vos et al. (2003). The aim of this study therefore was to determine the concurrent validity of the adjusted SQUASH in physically disabled and chronically ill patients.
Determining the validity of the adjusted SQUASH
The validity of an instrument is the extent of which it truly assess the exposure of interest (Welk, 2002). Because physical activity is a multidimensional exposure it is difficult to find an absolute golden standard for it. Instead, in determining the validity of the adjusted SQUASH it has to be compared to objective data that resembles the individual physical activity pattern of patients. This is called concurrent validity.
Multiple techniques can be used for obtaining objective information about physical activity behaviour. Gyroscopes, pedometers, diaries, accelerometers and heart rate monitors have been used in similar studies (Lamonte & Ainsworth, 2001; Montoye & Henry, 1996; Sirard & Pate, 2001). All devices have their own benefits and limitations. Accelerometers have been proven valid in detecting activity patterns (Wendel-Vos et al., 2003). However, these devises seem to be less accurate in detecting changes in more-energy consuming gait patterns which patients of our target population might have (Wezenberg et al., 2013). Heart rate monitors can distinguish between these differences because heart rate is a physiological variable directed related to oxygen uptake. Nonetheless, heart rate monitors as a single-measurement device are unreliable because changes in hart rate can be the cause of many other factors such as temperature, stress and dehydration (Crouter et al., 2008).
A device that incorporates both acceleration and heart rate is the Actiheart (CamNtech™). It combines these two variables into a single unit activity score which resembles the total physical activity behaviour. The Actiheart has proven to be a valid instrument in monitoring physical activity in both healthy subjects (Brage et al., 2005) as in a variety of patients groups, for example free-living women with COPD (Farooqi et al., 2013) and children with Spina Bifida (de Groot et al., 2013). To establish the concurrent validity of the adjusted SQUASH, it will be compared to the physical activity monitor Actiheart in several ways.
Methods
Participants
Forty persons participated in this study. Inclusion criteria to participate were being at least eighteen years old, having a physical disability and/or chronic disease and being post-rehabilitation. Exclusion criteria to participate were being completely wheelchair dependent and/or having a mental impairment. Patients were recruited from several sources. Most were recruited from local patient activity groups, patient associations and sport clubs for disabled people in Groningen, Friesland and Drenthe. Others were recruited because of close friendly bonds with the researchers. All patients signed an informed consent and were told that withdrawing from this study was possible at all times without having to declare reason(s). Measurement started at the end of autumn 2015 and continued until the spring of 2016. No large weather fluctuations were present. All the study procedures were approved by the ethics committee of the University Medical Centre Groningen.
Study procedure
When a patient indicated to be interested in participating, one or more members of the research team visited the patient at their home for a first visit. During the first visit the patient read an information letter and signed an informed consent. The patients also filled-in a form with personal information. Bodyweight and height were measured by the researchers. Patients were provided with detailed instructions on how to use the Actiheart and how to fill in the questionnaires.
Subsequently, the researchers attached the Actiheart directly below the chest as shown in Figure 1. The Actiheart was attached using two ECG electrodes. One electrode was adhered at V1 or V2 (fourth intercostal) and the second one was placed approximately 10 centimetres away on the left side. The electrodes used were 45MM Stud Adaptor ECG’s (Covidien™, Medtronic™). Patients were instructed to remove the Actiheart when showering, bathing or swimming. They were shown how to remove and re-attach the device from the electrodes.