Evaluation of a personalised adherence intervention to improve photoprotection in adults with Xeroderma Pigmentosum (XP): protocol for the trial of XPAND

A personalized and systematically designed adherence intervention improves photoprotection in adults with xeroderma pigmentosum (XP): results of the XPAND randomized controlled trial

BACKGROUND

Poor adherence to photoprotection in xeroderma pigmentosum (XP) increases morbidity and shortens lifespan due to skin cancers.

OBJECTIVES

To test a highly personalized intervention (XPAND) to reduce the dose of ultraviolet radiation (UVR) reaching the face in adults with XP, designed using known psychosocial determinants of poor photoprotection.

METHODS

A two-arm parallel group randomized controlled trial, including patients with suboptimal photoprotection to receive XPAND or a delayed-intervention control arm that received XPAND the following year. XPAND comprises seven 1 : 1 sessions targeting photoprotection barriers (e.g. misconceptions about UVR) supported by personalized text messages, activity sheets and educational materials incorporating behaviour change techniques. The primary outcome, mean daily UVR dose to face across 21 days in June-July 2018, was calculated by combining UVR exposure at the wrist with a face photoprotection activity diary. Secondary outcomes were UVR dose to face across 21 days in August 2018, time spent outside, photoprotective measures used outside, mood, automaticity and confidence to photoprotect. Financial costs and quality-adjusted life years (QALYs) were calculated.

RESULTS

Sixteen patients were randomized; 13 provided sufficient data for primary outcome analysis. The XPAND group (n = 8) had lower mean daily UVR dose to face [0.03 standard error of difference (SED) (SD 0.02)] compared with controls (n = 7) [0.43 SED (SD 0.17)] (adjusted difference = -0.25, P < 0.001, Hedge's g = 2.21) at the June 2018 assessment. No significant between-group differences were observed in time spent outside, photoprotection outside, mood or confidence. The delayed-intervention control showed improvements in UVR dose to face (adjusted difference = -0.05; Hedge's g = -0.1), time outside (adjusted difference = -69.9; Hedge's g = -0.28) and photoprotection (adjusted difference = -0.23, Hedge's g = 0.45) after receiving XPAND (June 2019 assessment). XPAND was associated with lower treatment costs [-£2642; 95% confidence interval (CI) -£8715 to £3873] and fewer QALYs (-0.0141; 95% CI -0.0369 to 0.0028).

CONCLUSIONS

XPAND was associated with a lower UVR dose to face in patients with XP and was cost-effective.

Identifying the psychosocial predictors of ultraviolet exposure to the face in patients with xeroderma pigmentosum: a study of the behavioural factors affecting clinical outcomes in this genetic disease

Background

For patients with xeroderma pigmentosum (XP), the main means of preventing skin and eye cancers is extreme protection against ultraviolet radiation (UVR), particularly for the face. We have recently developed a methodology for objectively measuring photoprotection behaviour (‘UVR dose to facial skin’) and have found that the degree of photoprotection varies greatly between patients with XP. We have previously identified factors affecting photoprotection behaviour in XP using a subjective measure of photoprotection. Here, we have used this objective methodology to identify the factors which determine photoprotection behaviour in XP.

Methods

We studied 29 psychological, social, demographic and clinical variables in 36 patients with XP. We have previously objectively measured UVR protection (by measuring the dose of UVR reaching the skin of the face over a 3-week period) in these patients. Here, we use linear mixed-effects model analysis to identify the factors which lead to the differences in degree of photoprotection observed in these patients.

Results

Psychosocial factors accounted for as much of the interindividual variation in photoprotection behaviour (29%) as demographic and clinical factors (24%). Psychosocial factors significantly associated with worse UVR protection included: automaticity of the behaviours, and a group of beliefs and perceptions about XP and photoprotection known to associate with poor treatment adherence in other diseases.

Conclusions

We have identified factors contributing to poor photoprotection in XP. Identifying these potentially reversible psychosocial features has enabled us to design an intervention to improve photoprotection in patients with XP, aiming to prevent skin and eye cancers in these patients.

Improving photoprotection in adults with xeroderma pigmentosum: personalisation and tailoring in the 'XPAND' intervention

BACKGROUND

Individualised behaviour change interventions can result in greater effects than one-size-fits-all approaches. Factors linked to success include dynamic (vs. static) tailoring, and tailoring on behaviour, multiple theoretical variables, and participant characteristics. XP is a very rare (∼100 UK patients) genetic disease, involving an inability to repair ultraviolet radiation (UVR)-induced damage, resulting in skin cancers and eye damage from an early age, and mean life expectancy of 32-years. Management involves rigorous UVR photoprotection, which is often inadequate, and no interventions have been published. UK-based care is personalised and delivered by a multidisciplinary team at the National XP Service in London. Following an intensive, mixed-methods formative phase with patients diagnosed with XP (n-of-1, qualitative interviews, objective UVR measurement, cross-sectional survey) and relevant stakeholder consultation (clinical and patient/public teams), the 'XPAND' intervention was developed. This paper describes the comprehensive and novel tailoring and personalisation processes used to deliver the intervention.

METHODS

XPAND consists of core and personalised modules targeting cue-based (time of day, weather, symptoms), belief-based (motivation, priority), self-regulatory (effort, barriers, planning), and emotional (stress, self-consciousness, mental exhaustion) factors, social support, disclosure, habit, and willingness, using appropriately-matched BCTs. A-priori, phase I data and a baseline profiling questionnaire (data sources) were used to allocate modules to participants ('personalisation') and to adapt module content ('tailoring'). Iterative decisions about delivery were based on patient response to feedback, identification of additional barriers (e.g. reasons for varying protection across contexts), and emergence of new barriers as improvements in protection were attempted or achieved (e.g. appearance concerns).

CONCLUSIONS

Dynamic multi-level personalisation and tailoring based on mixed-methods in XPAND allowed for insights and decision-making not possible with cross-sectional quantitative or qualitative methods alone. Data collection and allocation/adaptation methods may be of use in other rare conditions where small patient numbers mean that within-participant, individual-level delivery is well-suited and feasible.

Why? What? How? Using an Intervention Mapping approach to develop a personalised intervention to improve adherence to photoprotection in patients with Xeroderma Pigmentosum

Background: Intervention Mapping (IM) is a systematic approach for developing theory-based interventions across a variety of contexts and settings. This paper describes the development of a complex intervention designed to reduce the dose of ultraviolet radiation (UVR) reaching the face of adults with Xeroderma Pigmentosum (XP), by improving photoprotection. XP is a genetic condition that without extreme UVR photoprotection, leads to high risk of developing skin cancer.

Methods: The IM protocol of 6 steps was applied, involving comprehensive mixed-methods formative research. Key stakeholders (XP clinical staff and Patient and Public Involvement Panel), were instrumental at every step. Behaviour change methods were informed by the IM taxonomy, therapeutic approaches (e.g. ACT, CBT) and coded according to the taxonomy of behaviour change techniques (version 1).

Results: We designed a personalised modular intervention to target psychosocial determinants of photoprotective activities that influence the amount of UVR reaching the face. Content was developed to target determinants of motivation to protect and factors preventing the enactment of behaviours. Participants received personalised content addressing determinants/barriers most relevant to them, as well as core ‘behaviour-change’ material, considered important for all (e.g. SMART goals). Core and personalised content was delivered via 7 one-to-one sessions with a trained facilitator using a manual and purpose designed materials: Magazine; text messages; sunscreen application video; goal-setting tools (e.g. UVR dial and face protection guide); activity sheets. Novel features included use of ACT-based values to enhance intrinsic motivation, targeting of emotional barriers to photoprotection, addressing appearance concerns and facilitating habit formation.

Conclusion: IM was an effective approach for complex intervention design. The structure (e.g. use of matrices) tethered the intervention tightly to theory and evidence-based approaches. The significant amount of time required needs to be considered and may hinder translation of IM into clinical and non-academic settings.