Cancer is a disease that greatly changes the life of the patients throughout their treatment. Caregiver assistance in daily activities not only limited to personal care or household care, but also as psychological support, can be crucial for many patients.1–5 In this regard, the informal caregiver has played an essential role throughout history being recognized by the World Health Organization.6

The impact on health that informal caregivers of cancer patients are exposed to have been contrasted with those of other diseases,7–9 showing that the cancer caregivers are those who reported greater levels of physical burden and psychological distress5 and significant impairment across all health outcomes.10 Therefore, to study the time spent on informal care and its economic value is significant to identify the clinical and social magnitude of a disease, its family repercussion and stablish public policies.

Fortunately, the interest in including informal care in cost of illness studies has increased on the last years due to the significance of these results as part of the economic impact of the diseases. In this regard, recent studies have evaluated economically the informal care received by cancer patients8,11–13 in diagnoses such as prostate,14 lung,15 colorectal,15–17 or breast cancer.18 Nevertheless, the demand of informal care greatly varies depending not only on the diagnosis, but also depending on the sociodemographic and clinical characteristics of the patients and caregivers as well as on the phases of the treatment.5,12,14–19 Just four studies have evaluated economically the care giving across different phases of the cancer treatment,15–18 but none of them have valued it in a longitudinal and long-term way. Neither, any study has statistically examined the main determinants and differences that influence in the time spent on informal care in each phase of the treatment.

Our previous study identified the main factors related to the use or not of informal care in blood/haematological cancer patients between phases of the treatment,20 but no further information exists. We will go in depth of those results and our two objectives here are firstly, to quantify the informal care time given to blood cancer patients in the different phases of the treatments and its monetary value; and secondly, to estimate sociodemographic and clinical determinants associated with the time of informal care provided in each phase.

A total of 139 questionnaires were received (60.43% response rate) of which 123 patients reported having received informal care at some phase in the treatment (88.49% of survey respondents). 51.22% (n=63) of the patients were male and the average age was 46. Descriptive static and dynamic variables of patients and informal caregivers are shown in Tables 1 and 2.

The average number of estimated months of care was around 8 during the short-term and 7 during the medium-term. More than 50% (n=64) of the patients reported receiving more than 8hours/day of informal care in the pre-transplant phase (Table 2). This may be due to the aggressiveness of the chemotherapy treatment to which the patient is subjected diminishing their health status. During the first year after the transplant, the daily hours of informal care are more than 8 in 39.02% (n=48) of cases and between 2-4hours/day in 24.39% of cases (n=30). This variation may be due to possible complications after the transplant in some patients. However, in phase 3, 66.67% (n=82) of patients reported having received less than 2hours of care per day. The progressive reduction in time of informal care is related to health status in each phase of the treatment as we will see in the logistics model, but also Table 3 reflects that patients who had a bad or very bad state of health reported receiving more than 8hours of care a day in the short and medium term. However, in the long-term, patients with very bad or bad health status received between 2-4hours of care a day. This can be justified by the physical and psychological exhaustion of the informal caregivers themselves over time given the intensity in care during the previous phases.9,34

The average monetary valuation of the hours of informal care received during the pre-transplantation phase translates into a value of €3,409, €2,800 and €2,192 per month using the PGM, in cases where the hours of care received are made up entirely of personal care, domestic care and at home, or a mix of both respectively. This value is rounded up to €1,505/month using the OCM (Table 4). This monetary value drops significantly in the second and third phase as a consequence of the reduction in the number of hours of care, ranged from €854/month to €701/month using the PGM to 393 €/month by using the OCM in the third phase (Table 4).

Table 5 shows the determinants associated with the number of hours of informal care received by the patients during phase 1 and 2. Variables whose estimated parameters were statistically significant were the type of diagnosis, the health status and the level of education of the patient (results of models in Appendix 3 online). The likelihood of receiving more than eight hours of informal care during the pre-transplant phase is 22% higher in patients diagnosed with acute leukaemia than in patients diagnosed with lymphoma. This is due to their chemotherapy treatment which is much more aggressive than the rest of diagnoses in this phase.1,35 No significant differences between the lymphoma and the rest of diagnoses are shown. On the contrary, during the first year, the diagnosis is not a relevant determinant, its effect being absorbed by the type of transplant, which takes centre stage in this phase. Patients who have undergone an unrelated allogeneic transplant were 33.5% more likely to receive more than 8hours of care, compared to patients who have received an autologous transplantation. This is due to the complications associated with this type of transplant, such as infections, respiratory and cardiovascular diseases or graft-versus-host disease. In the long-term (Table 6) the patients with multiple myeloma are the ones who are 26.7% more likely to receive more than 2hours compared with patients diagnosed with lymphoma. The justification is that, while their current treatment has substantially improved in recent years, the probability of relapsing into the disease 3-4 years after the transplant is 90%,35 so the long-term care need is greater. On the contrary, the majority of patients who survive acute leukaemia will get back to a satisfactory level of physical, emotional well-being and daily activity.1

Regarding the state of health, those patients who show a good or very good health status in the phase 1 and 2 are 32% and 25.9% more likely to receive less than 2hours of informal care in these phases compared with those patients who have a bad or very bad health status (Table 5). Data shows that there is a decreasing trend in the probability of receiving more number of hours of care for these patients. At long term, patients who show a better health status are 45.8% less likely to receive more than 2hours than those who show worse health status (Table 6).

Finally, a third relevant variable is the educational level (Table 5). In regards to this, those patients with high educational level are 11.3% more likely to receive less than 2hours of daily care during the pre-transplant than those that have a low educational level, and a minor probability of 20.1% of receiving more than 8hours/day. In the first year after the transplantation the significance of influence is maintained, however, from the first year onwards, the educational level is not statistically significant, while other determinants such as marital status and age were, as explained in a previous study.20

We found that primary informal care varies greatly between stages of the treatment. In our study, blood cancer patients receive more than 8hours per day during the pre-transplant period (52.03% of the patients), but there is a progressive reduction of the number of hours received between phases, being lowest in the long-term. Therefore, the economic value associated with such care varies seriously between phases. These results were expected as the first and second periods involve aggressive treatments, complications, days of hospitalization and worse health status. The figure of formal caregiver is referred to as a complement in less than 10% of patients given that both caregivers were caring at the same time, hence we follow the line of other works and highlight the relevance of the informal caregiver in cancer patients.3,10,15–17,20,34

Several limitations of this study should also be noted. Firstly, the analysis was performed in patients diagnosed with haematologic neoplasm who had undergone stem cell transplantation as a minimum in the previous year. This selection was done with the aim of analysing the informal care received not only at the phase of chemotherapy but in the transplantation phases characterized by health complications. Secondly, the recall method used in the questionnaire is not as reliable as a diary-based method given that the patients had to remember the amount of care received. Therefore, there could be a bias based on the memory. However, it is the best method given our study design.26 In order to reduce the possible bias, intervals in the hours of care questions were established. A third limitation refers to the response bias which reduces the sample. Further studies with larger samples and different types of cancer are expected in order to expand and compare the results described.

This is the first study which analyses the longitudinal and dynamic way the informal care provided in the long-term to cancer patients, specifically on blood cancer patients. Few studies have explored the impact of informal care to cancer patients applying two alternative valuation approaches to value the time cost, hence our results could be used in economic evaluations on health technology assessment on haematological cancer (data hitherto unknown). Furthermore, these results can be relevant worldwide for the design of private insurances of cancer and the design of programs by public decision-makers to establish economic forecasts in the case of a non-availability of informal caregivers.

Miguel Ángel Negrín Hernández.

The corresponding author on behalf of the other authors guarantee the accuracy, transparency and honesty of the data and information contained in the study, that no relevant information has been omitted and that all discrepancies between authors have been adequately resolved and described.

M. Ortega-Ortega was the principal researcher, took primary responsibility for the paper and collected the data. R. Montero-Granados, J.D. Jiménez-Aguilera and M. Ortega-Ortega analyzed, interpreted and discussed the results. M. Ortega-Ortega wrote the first draft of the manuscript and the rest of the authors helped in the successive reviews up to the final version. All the authors have approved the final version.

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