Integrating stages of change models to cast new vision on interventions to improve global retinoblastoma and childhood cancer outcomes

Abstract

Background: Retinoblastoma, the most common intraocular tumor globally, represents a curable cancer when diagnosed early and treated promptly. Delay to diagnosis, lag time prior to treatment initiation, and abandonment of treatment including upfront treatment refusal, represent stark causes of high retinoblastoma mortality rates in low- and middle- income settings, particularly regions in Africa. While a health delivery-based approach has been a historic focus of retinoblastoma treatments globally and is essential to quality care, this is necessary but not adequate. Retinoblastoma is a compelling disease model to illustrate the potential insights afforded in theory-informed approaches to improve outcomes that integrate public health and oncology perspectives, prioritizing both health service delivery and social efficacy for cure.

Discussion: Given that barriers to appropriate and timely diagnosis and treatment represent main contributors to mortality in children with retinoblastoma in resource-limited settings such as certain areas in Africa, an important priority is to overcome barriers to cure that may be predominantly socially influenced, alongside health delivery-based improvements. While Stages of Change models have been effectively utilized in cancer screening programs within settings of economic and cultural barriers, this application of health behavior theory has been limited to cancer screening rather than a comprehensive framework for treatment completion. Using retinoblastoma as a case example, we propose applying stage-based intervention models in critical stages of care, such as the Precaution Adoption Process Model to decrease delay to diagnosis and a Transtheoretical Model to increase treatment completion rates in resource-limited settings.

Summary: Stage-based theories recognize that improved cure and survival outcomes will require supportive strategies to progress households, communities, and social and economic institutions from being unaware and unengaged to committed and sustained in their respective roles. Applying a stage-based model lens to programmatic interventions in resource-limited settings has potential for visible improvement in outcomes for children with retinoblastoma and other cancers.

Figure 1

Delineating lag time. Delineating total lag time (red) prior to initiation of curative therapy as composed of delay to diagnosis (purple) and delay to treatment initiation (blue).

Figure 2

Duration (in months) of delays to retinoblastoma treatment in Africa. L = Delay from symptom to treatment, D1 = Delay from symptom onset to diagnosis, D2 = Delay from diagnosis to treatment initiation. * = month duration obtained through personal communication with authors and included with authors’ kind permission (unpublished data). Cameroon L = 24 months, n = 57 (Kagmeni2013*) [23]. Congo L = 24 months, n = 49 (Lukusa2012) [9]. Nigeria D1 = 6.3 months, n = 26 (Bekibele2009) [24]. Tanzania D1 = 10 months, n = 91 (Bowman2008) [17]. Mali D1 = 50 months, n = 55 (Boubacar2010) [18]. Tunisia D1 = 10 months, n = 35 (Frikha2009) [16]. Namibia D2 = 3.5 months, n = 15 (Wessels1996) [25]. Sudan D1 = 10 months, n = 25 (Ali2011) [26]. Burkina Faso, D1 = 11 months, n = 3 (Nikiema2009) [27]. Kenya D1 = 6.8 months, n = 206 (Nyamori2012*) [20].

Figure 3

Tri-lineage model of delay with description of possible causation.

Figure 4

Precaution adoption process model applied to “social interventions” for earlier diagnosis of retinoblastoma in LMIS.

Figure 5

Transtheoretical model (Linear) for retinoblastoma treatment. The linear model represents a staged progression from precontemplation through maintenance. Maintenance in oncology care represents a starting point, as treatment completion through cure (remaining actively “maintained” through treatment) is the ultimate goal.

Figure 6

Reality of transtheoretical model (Lived) for retinoblastoma treatment legend: The spiral model represents the lived experience as an often non-linear experience of delay to start, regressions, and recycling through stages. The lighter the shade, the more mature the progression. Red in this model represents warning of abandonment as upfront treatment refusal or failure to complete therapy, representing regression or a recycling backward in stage progression. Blue represents a forward movement. Green represents an intervention which re-addresses family-efficacy and decisional balance to foster forward progression. Bold shades warrant additional support as patients may feel vulnerable during the newness of entrance into a stage, embarrassed by regression, or even ashamed about returning to care due to regression or recycling backward in stages.