Follow-up after surgical treatment for intermittent claudication (FASTIC): a study protocol for a multicentre randomised controlled clinical trial

Complex interventions are widely used in the health service and defined as interventions.

which comprise multiple interacting component [13]. Medical Research Council (MRC) guidelines for developing and evaluating complex interventions provide guidance to researchers and strengthen the internal and external validity and add value to health care research. Several steps are recommended for the systematic development of complex interventions such as problem identification, the systematic identification of evidence, identification or development of theory, determination of needs, the examination of current practice and context, modelling the process and expected outcomes leading to final element: the intervention design [13, 14].

Person-centred care (PCC) is a method of care-giving that has been implemented over the last few years. It has been shown to improve self-efficacy, adherence to prescribed medication and shorten hospital stay [15]. Person-centred care (PCC) means involvement of the patients as partners in their care. The core of a person-centred approach is allowing the patient to be part of their care by letting them describe their situation from their own point of view and putting their views at the centre of care. This could also be described as a collaborative process of decision-making between patients and their health care provider that takes into account the patient’s values and preferences and clinical evidence [16]. A personal health plan is made based on the information exchanged during the narrative communication. This health plan includes goals, strategies, and terms of evaluation, and is jointly developed by the patient and the professional [17]. The process of practicing PCC in health care as described by Ekman et al. contains three components: patient narratives, partnership, and safeguarding the partnership [17]. Patient narratives is about sharing of information and initiating partnership between the patient and the care giver. Narrative communication involves learning from each other, creating common understanding of the illness, and learning about the patient’s resources, limitations, and expectations. This provides the professional a good basis for discussing and planning care and treatment with the patient [17]. A person-centred care approach added to the usual care of patients with acute coronary syndrome improves general self-efficacy, which is an important factor for effective self-management of illness [18].

Effective public health, health promotion, and chronic disease management programmes help people maintain and improve health, reduce disease risks, and manage chronic illness. Health behaviour theory can play a critical role throughout the programme planning process and for the effect of the intervention. According to social cognition theory, self-efficacy, goals, and outcome expectancies are three main factors that can affect the possibility that a person will change a health behaviour are [19].

Secondary prevention therapy requires engagement, participation, and adherence from the patient. Patients with PAD require disease-specific information, adequate support enabling them to manage recommended behavioural changes [20] and to adapt to and live with chronic illness [21]. A large international registry on patients with established atherosclerosis reported an association between non-adherence to evidence-based secondary prevention therapies and a significant increase in risk for long-term adverse events, including mortality [22]. Adherence to medication has been reported to be as low as 30% [23] to 50% [22]. Non-adherence to medication after acute coronary syndrome tends to be lower immediately after discharge (20%) and increases to 54 and 53% at 6 months and 1 year after discharge, respectively [24]. Barriers to physical activity in patients with PAD are related to the pain experienced when walking [25], lack of knowledge about the condition and doubts that lifestyle changes, particularly physical activity, would improve their condition [20]. Therefore, providing clear and consistent information about the condition and detailed information regarding exercise, as well as mental support to enable behavioural changes, are important [20]. Furthermore, preventive treatment measures require a long-term follow up. A 20-min visit with a vascular surgeon in the standard follow-up after surgical intervention offers limited time to address the important questions of physical exercise, smoking, and medical adherence. Probably not all the patient’s barriers to lifestyle changes and medical adherence are identified in such a visit. A person-centred and health promotion approach might facilitate breaking barriers and increasing adherence to secondary prevention therapy for patients with IC. However, to the best of our knowledge, no such studies have been performed.

We hypothesise that a nurse-led, person-centred, health-promoting follow-up programme will increase adherence to BMT and reduce the risk for cardiovascular or cerebrovascular events compared with standard care.

The overall aim of the FASTIC study is to evaluate a nurse-led, person-centred, health-promoting follow-up programme compared with standard follow-up by a vascular surgeon after surgical treatment for IC.

The primary objective of the FASTIC study is to examine the effect of the above-mentioned programme on the patient’s adherence to prescribed BMT (primary outcome) and reduce the risk for cardiovascular or cerebrovascular events. Furthermore, secondary objectives of the FASTIC study are to investigate the effect of the above-mentioned programme on patient-reported outcomes (HRQoL, health literacy, belief of medication, and adherence to medication), health outcomes, and participants’ experience of the intervention programme compared with the standard follow-up.

The FASTIC study is a multicentre, randomised controlled clinical trial. Patients will be recruited from two sites; the Departments of Vascular Surgery at Södersjukhuset and at Karolinska University Hospital, both in Stockholm, Sweden. Patients with IC are referred to the vascular surgical outpatient clinics in one of these hospitals by a primary care physician.

The Stockholm County is a geographical area covering the City of Stockholm and surrounding area with approximately 2.3 million inhabitants. This region has two centres for vascular surgery, the Karolinska University Hospital and Södersjukhuset, both of which are located near the city centre. On average, 350 open surgical interventions and endovascular interventions for patients with IC are performed at these two centres every year according to the Swedish National Registry for Vascular Surgery (Swedvasc). No major vascular surgery is performed outside these centres and all patients in the Stockholm County with IC who may require arterial surgical intervention are referred to one of these centres. During the first visit at the vascular surgical outpatient clinic, diagnosis and requirement for revascularisation are decided by a vascular surgeon and recorded in the patient’s medical record. This decision is based on clinical symptoms and circulatory assessments, including the ankle brachial index (ABI), Duplex ultrasound, and/or computed tomography angiography. Cessation of smoking for at least 3 months prior to surgery is required. Patients are prescribed statins and antiplatelet agents at this point if not previously prescribed.

Patients who fulfil all the inclusion criteria and none of the exclusion criteria mentioned below are eligible for the study.

The sample size was calculated based on results from previous literature regarding primary outcome (adherence to medication) in cardiological studies [22, 26]. Statistical power analysis using IBM SPSS Sample Power 3 (IBM Corp., Armonk, NY, USA) showed that a required sample size of 186 participants was needed to detect a statistically significant increase in adherence to prescribed BMT from 50 to 70% (power, 0.80; significance value, 0.05; two-sided). We plan to recruit 210 participants and expect a 10% drop-out.

Patients who are eligible for the study are identified by one of the study nurses at each of the two outpatient clinics. Written information about the FASTIC study, including a consent form, is sent by mail to the eligible patients. When the patients arrive to the vascular surgical ward prior to surgery, the study nurse provides oral information about the study and asks for participation. If consent is obtained, baseline data are collected. The surgery is performed and randomisation to either an intervention programme (intervention group) or a standard care programme (control group) is performed immediately after surgery by a study nurse. In some cases, the endovascular procedure may not result in revascularisation. The patient can still be randomised to the FASTIC study if a decision is made to reschedule to open surgery. If no further surgical interventions are planned, the patient will be withdrawn from the study. Figure 1 shows a description of the study flow. A time schedule of study enrolment, interventions, and assessments is shown in Fig. 2.

Randomisation is performed by sequence generation using secure computer-generated random numbers. The allocating study nurses have no insight to block randomisation factors behind the sequence generation process. Patients who meet all study criteria and consent to participate are randomised to either the intervention group or the control group. No blinding will be applied in this study.

The Framingham Risk Score (FRS) [32] will be used to calculate the predicted 10-year risk of cardiovascular and cerebrovascular events. FRS sex-specific prediction formulas are based on general cardiovascular risk factors (age, systolic blood pressure, treatment for hypertension, smoking status, diabetes, and total and high-density cholesterol levels). The FRS will be combined with the ABI, which have been shown to improve the accuracy of risk prediction [33].

Resting blood pressure, weight, height, calculation of body mass index (BMI), and waist circumference will be measured at study enrolment and at 1 year after revascularisation. The patients will also be asked to state their perceived pain-free walking distance.

ABI, defined as the ratio of systolic blood pressure at the ankle and systolic blood pressure in the upper arm, will be measured and calculated at study enrolment, after 4–8 weeks, and at 1 year after revascularisation.

Graft patency will be assessed using the ABI and the patients’ history. If there are any indications of re-occlusion, a Duplex ultrasound examination will be performed.

Beliefs about medication (BMQ) will be measured by the BMQ questionnaire [34]. This questionnaire consists of two parts, which are the BMQ-General and BMQ-Specific. The BMQ-General comprises three four-item scales assessing general beliefs about pharmaceuticals as a form of treatment. The General Harm scale assesses beliefs about the degree to which medicines are essentially harmful. The General Overuse scale assesses beliefs about whether doctors place too much emphasis and trust on medicines. The General Benefit scale assesses beliefs about the degree to which medicines are fundamentally beneficial. The BMQ-Specific comprises two scales assessing beliefs about the necessity of a specific treatment for controlling an illness (5 items) and concerns about potential adverse consequences of taking it (6 items). Each item has a five-point response scale (1 = strongly disagree to 5 = strongly agree). The validity of this questionnaire has previously been confirmed [34, 35]. Agreement to use the BMQ questionnaire has been obtained from Professor Rob Horne.

Health literacy (HL) will be measured using the Swedish version of the European Health Literacy questionnaire, HLS-EU-Q16 [36]. The short version of this questionnaire consists of 16 items. These items focus on four HL dimensions reflecting perceived ease or difficulty in an individual’s ability to accessing/obtaining health information, understanding health information (not only in written form), processing/appraising health information, and applying/using health information. Response choices are “very easy”, “easy”, “difficult”, and “very difficult” [36].

HRQoL will be measured using the Swedish versions of EQ-5D 5 L [37, 38] and the Vascular Quality of Life Questionnaire (VascuQol-6) [39]. The EQ-5D 5 L is a generic instrument from the EuroQol Group [40] and measures health in five dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression). Each dimension has five levels of severity (no problems, slight problems, moderate problems, severe problems, and extreme problems). This questionnaire includes EQ-VAS, where the participant grades their own perceived health status on a visual analogue thermometer scale with endpoints of 0–100 (0 = the worst health you can imagine and 100 = the best health you can imagine) [37]. VascuQoL-6 is a disease-specific instrument and consists of six items (symptom, pain, social life, emotional, and two items in activity) and each item has a four-point response scale [39]. Previous studies have shown that VascuQol-6 is a valid and reliable instrument for assessing HRQoL in patients with PAD [41].

The General Self Efficacy (GSE) scale measures people’s beliefs in their abilities to cope with a variety of difficult demands in life. The GSE scale consists of 10 items rated on a four-point Likert scale (1 = not at all true, 2 = hardly true, 3 = moderately true, and 4 = exactly true), yielding a total score between 10 and 40. The GSE scale was originally developed in Germany [42] and has been validated in Swedish [43].

Patient-experienced quality of care will be measured by using the questionnaire Quality from the Patient’s Perspective (QPP) [44]. In QPP, the items are evaluated by the respondent in two ways. To measure the subjective importance that the person ascribes to the various aspects of care, each item is related to the statement “This is how important it was to me …” . A four-point response scale ranging from 1 (of little or no importance) to 4 (of the very highest importance) is used for all items. To measure the perceived reality of the quality of care, each item is related to the sentence “This is what I experienced …” . In this part of QPP, a four-point response scale ranging from 1 (do not agree at all) to 4 (completely agree) is used. The short version of QPP will be used in the study [45]. The validity of QPP has been tested previously [44, 45].

A screening instrument of unhealthy lifestyle habits from the Swedish National Board of Health and Welfare’s National Guidelines for Methods of Preventing Disease will be used when establishing the self-care plan with the participants in the intervention group and during the follow-up sessions. This instrument includes items on tobacco use, alcohol intake, physical activity, and eating habits [11].

All electronic study data will be stored in a password-protected local database and participants will only be identifiable by their study number. All paperwork will be kept in a locked filing cabinet in a locked office.

Descriptive statistics will be used to describe baseline demographic and clinical data. Continuous variables will be summarised as mean (SD) or median (interquartile range), and categorical variables will be summarised as number (percentage). Comparisons between the intervention group and the control group will be made using the t-test and ANOVA for repeated measures, or the Wilcoxon rank-signed test and Kruskall–Wallis test according to the underlying distribution for continuous data. The chi-square or Fischer’s exact test will be used for categorical data. Logistic regression analysis will be performed for binary outcomes to adjust for confounding factors. All analyses will be performed according to the intention-to-treat principle. IBM SPSS version 23 or later (IBM Corp., Armonk, NY, USA) will be used for statistical analyses. The CONSORT 2010 statement will be followed when reporting the results [46].

The protocol has been designed according to SPIRIT Recommendations of the Standard Protocol Items: Recommendations for Interventional Trials [47]. A SPIRIT figure is available for this protocol (Fig. 2).

The FASTIC trial is currently ongoing with data collection in both study sites. Recruitment of participants started in June 2016 and was completed in November 2018.