Making sense of PRT utilization
This study showed the overall PRT utilization rate for EOL cancer decedents in the last year of life was 21.7% in BC. This rate was similar to those reported by Lavergne et al. [
6] in Nova Scotia (22.5%) for PRT utilization in last 9 months of life and by Huang et al. [
4] in Ontario (26.4%) for last 2 years of life.
When compared with Nova Scotia, our rates were lower for breast (19.6 vs. 31.5), melanoma (21.1 vs. 39.5) and prostate (15.2 vs. 27.6) cancer but similar for lung (45.7 vs. 37.3), colorectal (8.9 vs.9.9) and hematologic (15.6 vs.10.3) cancer. Because different variables were used in the Ontario study, PRT rates for only three cancer groups could be compared. Those with breast cancer in Ontario had higher rates of PRT use, (39.4 vs. 19.6), but similar rates for hematopoietic (18.6 vs. 15.6) and lung cancers (39.9 vs. 45.7) despite the difference of time frame reported i.e. 2 year rates in Ontario versus 1 year rates in this study. This study also found brain cancer decedents had the second highest RT utilization rate (36.9%) in the last year of life following after lung cancer; however, only 17.6% of decedents received RT deemed palliative by our definition. This is mainly because brain RT, although palliative by nature, is not likely to be coded as palliative in this data.
In this study, PRT utilization varied by such factors as age, diagnosis, survival time and geographic region. Those younger than 85 years of age, with primary lung cancer, survival time of 1.5-26 months from diagnosis, or residing less than 2 hours from a cancer centre had higher rates of PRT utilization. These results were similar to those identified by Lavergne et al. [
6], except for sex; they found being female was associated with declined PRT use. Huang et al. [
4] also reported higher likelihood of PRT use among those with younger age and those living near a cancer centre.
Possible reasons for reduced PRT use in older decedents was that they had more severe comorbidities, worse performance status or different treatment preferences that made PRT less suitable [
3,
4,
6]. The higher rates for decedents who survived 1.5-26 months may have been because those who had very short survivals may have been too sick to benefit from radiotherapy, as assessed by their oncologists. On the other side of the spectrum, those with longer survivals may have been quite well and asymptomatic, not needing cancer treatment, and may have even died of other causes. The variable rates observed across cancer groups are likely due to difference in symptom frequency/severity or cancer site-specific indications for radiotherapy or other palliative treatments.
Regarding regional differences in PRT use, the lowest PRT rates in this study were in the Northern (i.e. Northeast, Northern Interior), Vancouver Coastal (i.e. North Shore/Coast Garibaldi) and Interior regions (i.e. East Kootenay, Kootenay Boundary, Thompson, Okanagan). One likely reason for the low rates in the Northern region may have been that there was no cancer centre in the region at the time of this study, and decedents were generally referred to the Vancouver centre, which could have been many hours flight from many parts of the regions. Another was that North East and East Kootenay HSDAs are close to the neighbouring province of Alberta. It is possible that some decedents were referred to the radiotherapy centres in Alberta, which would not be captured in our data [
15]. These findings were consistent with other studies that showed the detrimental effect of increased travel time on reduced PRT use existed previously, affecting patients as early as 1986 [
15,
16].
One exception to the regional variation in PRT use was the Northwest HSDA in the Northern region which had the highest rate (28.6) in the province. This could relate to a high percentage of First Nation population residing in the region, whose travel may have been more likely to be paid for. Another was the Interior Okanagan HSDA that had rates (20.0) below the provincial average despite having a cancer centre in the region. One reason could be that 20-40% of the decedents in that HSDA were more than 2 hours drive away from the cancer centre. Another reason could be that pre-existing long wait lists for radiotherapy may have been a significant disincentive to refer patients for PRT, or patients may have died or been treated with other palliative measures prior to PRT becoming available to them.
Because of the methodology of this study, we were unable to examine other relevant patient, service and system related factors that may influence PRT utilization, such as functional status and symptoms [
13,
17], socioeconomic status [
4‐
6,
13], hospice care [
4], nursing home residency [
6], PRT consultation [
5,
6], hospital affiliation [
13], wait times [
18,
19], referral to a formal palliative care program [
20,
21], and physicians’ knowledge of PRT and how active they were involved in palliative care [
18]. The availability of formal Palliative Care programs and hospice care varies greatly among communities in British Columbia. Further work needs to be done to link the availability of these services to outcomes.
Appropriate PRT use in EOl cancer care
In this study, the proportion of EOL cancer decedents that received at least one course of PRT in the last 30 and 14 days of life were 5.0% and 2.2%, respectively. Guadagnolo et al. [
13] studied 15,287 SEER-Medicare decedents (≥65 yrs) who died from malignant diseases of lung, breast, prostate, colorectal, and pancreas from 2000 to 2007. In that study, 7.6% of the decedents received PRT within their last 30 days of life. The lower rate observed in our study may be partially explained by the differences in defining the study cohort as well as the reimbursement systems used in different health care systems. Despite the underutilization of PRT in end-of-life care in Guadagnolo et al. study [
13] and the others [
2,
17,
22], due to the relevance of nonclinical factors found with the use of PRT in the last month of life, we would argue that the lower rate we found in our study might indicate the accuracy of physician predictions on prognosis and thus ‘appropriate’ palliative care, especially with respect to geographic access. Lower rates are considered appropriate, as good palliative care for a patient who lives far away is through use of medication and avoidance of a long trip that might hasten their death and negatively impact their overall quality of life.
Some studies reported “optimal” PRT utilization rates based on empirical findings or model estimates. For instance, Huang et al. [
4] identified a subgroup of cancer decedents in Ontario who had more optimal PRT (2 year) access rate of 57.8%, which was above the average of 26.4% in their study population. This subgroup was made up of individuals who were less than 70 years of age, residents of medium and high income communities, diagnosed in a hospital with a cancer centre, and residing near cancer centres with better PRT access. Based on these findings, Huang et al. concluded that PRT was underutilized in Ontario. In our study, due to the lack of neighbourhood income data, we were not able to construct a comparable cohort to compare the ‘optimal’ PRT rate for BC EOL cancer decedents. It is impossible to truly asses if PRTs rates found in this study are “appropriate” or “inappropriate”, given the lack of individual decedent data about pain and symptom prevalence/severity, decedent functional status, and decedent treatment preferences. Nevertheless, the fact that PRT rates in our study varied by non-clinical factors such as age, travel time and geographic region does suggest underutilization of PRT in a subgroup of population with suboptimal access.
With the increased emphasis on monitoring EOL care, further work is needed to assess appropriateness of PRT rate for EOL cancer decedents in BC, and to develop benchmark rates that can be practically assessed in different geographic regions. Development of these benchmark rates may require richer data collected at the point of care as well as rigorous/robust methodology based on a sound scientific footing. Both aspects remain challenging in the current palliative/EOL care research but desire resolution in the future.
Study limitations and implications
This study has three limitations. First, the cause of death for decedents was not available at the time of data collection. Therefore the cohort consisted of decedents who died with rather than of cancer, which could under-estimate PRT rates. Second, this study used data collected for administrative purposes. Such clinical factors as symptom assessment and patient preferences at end of life were not available, which could provide reasons for PRT use. Third, PRT practice in BC may not be generalizable outside of BC, as practice varies by country and training, location and type of practice, experience and reimbursement.
To the best of our knowledge, this population-based study is the first of its kind providing data on the use of PRT for the end of life cancer population in BC. It is our hope that this information could be used by local cancer care providers and health care administrators for cancer care planning as well as researchers conducting end of life care research. We believe that the findings from this study have shed light on the issues of suboptimal PRT treatment received by a subgroup of the BC cancer population due to restricted geographic access. Identifying the subgroup who might be receiving suboptimal care at the end of life will help service planners target this population for quality improvement. Even though it is not an intention of this research to identify optimal PRT rates, findings from this study raises important questions and provides the base PRT utilization rate at the population level for future research. Lastly, this study will add province-specific data of BC to existing data available in other Canadian provinces on the subject of PRT utilization for palliation. This will increase the availability of data on provincial comparisons for future end of life research.