Colorectal cancer (CRC) is the third most common cause of death from cancer for Māori and, while it is more common among non-Māori, the incidence and mortality rates are increasing more rapidly for Māori than non-Māori.[[3]]

Bowel cancer survival rates are low for Māori compared to non-Māori.[[4]] The 5-year risk of death from bowel cancer is 59% for Pasifika and 47% for Māori compared to 38% for non-Māori and non-Pasifika.[[1]] Māori are more likely to have CRC diagnosed in the emergency setting. Māori are also more likely to present with bowel obstruction or perforation and require emergency surgery.[[5]] Patients who have CRC diagnosed in the emergency setting have poorer outcomes, with a higher stage at presentation, increased surgical complications and decreased survival.[[1,6,7]] Inequities observed in the Bowel Screening Programme (BSP) with the use of an inappropriate eligible age range for Māori may have also contributed to these outcomes.[[8]]

This evidence of inequity in CRC outcomes highlights the need to scrutinise all pathways into health services for Māori with an equity lens to determine how structural barriers are contributing to the greater burden of harm from CRC experienced by Māori.

Access to diagnostic colonoscopy is crucial to finding CRC earlier and at a less advanced stage to decrease the associated morbidity and mortality. Inequity in access to outpatient diagnoses, with the knowledge that acute diagnoses are associated with worse outcomes, may be a major contributing factor in the higher burden of CRC mortality among Māori. Inequity in accessing colonoscopies therefore has serious implications.

At Te Whatu Ora Counties Manukau (CM) during our study period (January to December 2018), patients referred for colonoscopy were required to organise their appointment with the Gastroenterology Department following an accepted referral. As of 2023 this system remains unchanged. Patients classified as urgent were contacted via phone and a procedure time was negotiated. For patients with non-urgent and surveillance colonoscopies a text or letter was sent to the patient. The patient then had 10 working days to make contact with CM to negotiate their procedure time. If no contact was made then the patient was removed from the waiting list and a letter sent to the patient and their general practitioner (GP) to inform them they have been “removed off the waiting list” (ROWL). If after this second contact the patient did initiate contact with CM, they were able to negotiate a time for their procedure. If still no contact was made in the next 5 working days, the patient was then advised by letter to see their GP for a re-referral for a colonoscopy.

We hypothesise that part of the reason Māori have a lower survival rate than non-Māori is due to decreased access to colonoscopy. This results in an increased rate of diagnoses being made in the acute setting where the stage is more advanced and rates of complications are increased, resulting in poorer survival outcomes.

This study aims to quantify any difference between Māori and non-Māori in access to colonoscopy at CM.

Methods

Positioning

This study incorporates an Indigenous Kaupapa Māori Research (KMR) positioning. This is reflected through inclusion of Māori leadership within the research team, putting Māori at the centre of the research question/objectives, rejection of cultural-deficit or victim-blame analyses and use of a conceptual framework that incorporates a structural determinants approach to critique issues of power, racism and privilege at a system (versus individual) level.[[9]]

Patients and variables

The data were obtained from CM Gastroenterology Department internal records and provided to the research team following local ethics approval from the Auckland Health Research Ethics Committee. A total of 7,184 patients had an accepted referral for a colonoscopy made to CM in 2018.

Descriptive variables included gender (recorded as male/female) and age (<25years, 5-year age bands and >85years). Prioritised ethnicities included in the referrals were grouped into Māori, Pacific, Asian, Other and NZ European as per the New Zealand Ethnicity Data Protocols.[[10]] Domicile codes were used to classify each patient’s level of deprivation into quintiles using the New Zealand Deprivation Index 2013 (NZDep2013; Quintile 1 being least deprived to Quintile 5 being most deprived).[[11]] All referrals when accepted were graded by referral priority as urgent (aim to complete within 2 weeks), semi-urgent (aim to complete within 8 weeks) and surveillance (2 years). Referral sources were recorded as internal (referrals from within CM) and external (referrals from primary healthcare).

Outcome variables included: colonoscopy performed or ROWL with reason listed as “unable to contact”. No other reasons for ROWL were recorded.

There were 159 patients excluded due to incomplete data; 155 patients had missing ethnicity data and another four were missing deprivation data. Therefore, a total of 7,025 patients were included in the univariate and multivariate analyses.

Statistics

Univariate analysis was used to determine the predicted odds ratio (OR) for an accepted colonoscopy referral to result in the patient being removed off the waiting list due to being classified as unable to be contacted by gender, age, ethnicity, deprivation quintile, referral priority and referral source.

Logistic multivariate analysis was used to determine the odds of removal off the waiting list per accepted referral by ethnicity with adjustment for gender, age, deprivation, priority and referral source.

The median number of days for a patient to be removed from the waiting list was compared by ethnicity, with p-values of less than 0.05 being taken as statistical significance.

Results

Overall patient and referral characteristics

In 2018, there were a total of 7,184 accepted referrals for colonoscopies in CM. There were 1,989 patients (27.7%) who were removed off the waiting list, with the reason for removal classified as “unable to contact”. There was no record of patients being removed from the waiting list for other reasons. Table 1 shows the outcome of these colonoscopy referrals grouped by gender, age, ethnicity, deprivation quintile, referral priority and referral source. This shows that 33.4% of Māori patients were removed off the waiting list compared to 24.1% of NZ European patients.

Univariate analysis

Māori patients were significantly more likely to be removed off the waiting list than NZ European patients (OR 1.5, 95% confidence interval [CI] 1.34–1.87) (Table 2). Pasifika and Asian patients were also more likely to be removed off the waiting list compared to NZ European (OR 1.94, 95% CI 1.66–2.27 and OR 1.30, 95% CI 1.12–1.49 respectively).

Women were statistically less likely to be removed off the waiting list than men (OR 0.89, 95% CI 0.80–0.99). There was no statistically significant difference between age groups, x[[2]] (7, N=7,184) = 4.75, p>0.05.

The patients residing in the most deprived quintile were significantly more likely to be removed off the waiting list than those patients residing in the least deprived quintile (Q1) (OR 1.33, 95% CI 1.14–1.55). Patients with external referrals were less likely to be removed off the waiting list than those referred internally (OR 0.84, 95% CI 0.75–0.95).

View Tables 1–3.

Multivariate analysis

After adjustment for gender, age, deprivation, referral priority and referral source, Māori patients were significantly more likely to be removed off the waiting list than NZ European patients (OR 1.68, 95% CI 1.40–2.02). Of note, the inequity between Māori and NZ Europeans increased when controlling for all variables in multivariate compared to univariate analysis (OR 1.68 vs 1.58 respectively). Similarly, inequities are seen for Pasifika and Asian patients compared to NZ Europeans (OR 2.30, 95% CI 1.92–2.75 and OR 1.39, 95% CI 1.20–1.61 respectively).

Median time to ROWL

The overall median time between a referral being received and a patient being removed off the waiting list due to being uncontactable was 52 days. We note that this is significantly longer than the 15 working days (equivalent to 21 days) that the department used as its guideline for managing accepted referrals.

The median time for NZ European patients was 56 days, compared to 48 days for Māori patients (Table 3). Māori patients have a statistically significantly shorter median time (8 fewer days) to arrange an appointment compared to NZ European patients (p<0.001).

Discussion

This study, using 1 year of referral data from CM, shows that Māori have significantly less access to colonoscopy services than NZ European patients. For each accepted referral Māori are less likely to have a colonoscopy performed. Differences in gender, age, deprivation, referral priority and referral source between NZ European and Māori patients do not explain the inequities in colonoscopy access; rather, they appear to make the inequity worse. Furthermore, Māori patients have less of an opportunity to negotiate a colonoscopy appointment time as they are classified as “unable to be contacted” and removed off the waiting list on average 8 days sooner than NZ European patients. This suggests that there is a bias in the current system that systematically worsens access to colonoscopies for Māori patients assessed clinically as requiring this intervention. In addition to other known access barriers for Māori (e.g., unmet need in primary care),[[12]] it is possible that colonoscopy access inequities are also contributing to disproportionate CRC-associated morbidity and mortality for Māori.

To achieve equity in CRC outcomes, every point along the diagnosis and treatment pathways must have equity embedded in their design. As the gold standard diagnostic tool for bowel cancer, colonoscopy is a key part of the outpatient diagnostic pathway. Based on the findings of this study, improvements are required to enable equitable access for Māori to colonoscopies. Factors associated with how patients are removed off waiting lists for colonoscopies need further exploration to ensure that the system prioritises Māori for investigation, rather than de-prioritising them via early removal from waiting lists. This will require a significant shift away from potential victim-blame approaches that stigmatise patients who are unable to make contact (i.e., as being lazy or less worthy of ongoing follow-up).[[13]] Rather, a lack of contact should be seen as a marker of structural inequities requiring a greater investment of time and energy from health services to achieve the desired outcome (i.e., coordination and arrangement for colonoscopy access at a time that works for the patient).

In addition, the current system appears to be privileging NZ Europeans while inadequately serving Māori, Pasifika and Asian ethnicities. The fact that all non-NZ European ethnicities are being disadvantaged by the current system implies that there is structural privilege for NZ Europeans, rather than issues intrinsic to any specific minoritised ethnic grouping, causing this inequity. Understanding how both racism and privilege operate within health system delivery to create ethnic inequities in healthcare, including cancer care, outcomes is required.[[14]]

The Crown, and all its agencies, are obligated to achieve equity for Māori. This obligation reflects Māori Indigenous rights reaffirmed by Te Titiri o Waitangi and the United Nations Declaration on the Rights of Indigenous Peoples.[[15]] One of the three purposes of the Pae Ora (Healthy Futures) Act 2022 (Pae Ora) is to “achieve equity in health outcomes among New Zealand’s population groups, including by striving to eliminate health disparities, in particular for Māori”.[[16]] Under Pae Ora, Te Whatu Ora is required to design, deliver and arrange services to achieve this purpose.

Intrinsic challenges to outpatient colonoscopy access will need to be overcome. A review of barriers and enablers to the access of hospital services for Māori found practical barriers were more pronounced for Māori than non-Māori, owing to the greater experience of socio-economic deprivation among Māori, as well as barriers relating to experiences of racism in the health system and a lack of culturally safe settings, services and practitioners.[[17]] In the context of outpatient colonoscopies, practical barriers include the need to take time off work, arrange childcare, arrange transport to and from the procedure and arrange post-procedure support. In scheduling, the current system relies on patients speaking English and having access to a phone with credit to call back on. The pre-procedure change in diet, withholding of regular medications and bowel preparation ideally require careful explanation and an opportunity for patients to have queries and concerns addressed in a culturally safe way. These factors are likely to impact on the Māori outcomes observed and may also explain the large inequities observed for Pasifika compared to NZ Europeans in our findings. A Pasifika-led analysis of these factors is recommended.

We believe that clinical nurse specialists may contribute to improving equity for patients requiring a colonoscopy. Clinical nurse specialists can improve outcomes by providing information, service coordination and psychological support for patients.[[18]] Clinical nurse specialists are able to call patients, negotiate colonoscopy times, utilise interpreter services, check patients have received bowel preparation, reiterate the bowel preparation instructions, explain the indication and be available to take calls from patients if they have any further questions.

The current system at CM puts the onus on the patient to initiate contact and make time for a colonoscopy. This can lead to blame being put on the patients themselves for their limited access. The service attempts to absolve itself of its responsibility by notifying GPs of a patient's removal from the waiting list, rather than opening a dialogue with the patient to understand their individual needs and barriers. Therefore, we recommend changes to the booking process itself with all patients to be contacted via a phone call, and the option for these calls to be made outside of usual working hours (9am to 5pm). Where contact is still not made despite calls, texts and letters, a protocol of escalation, including contacting the patient’s next-of-kin, the referrer and their GP, needs to be established. Regular auditing is also required to review the time between a referral being received and first contact with the patient, to ensure that patients are being contacted and colonoscopies are scheduled in a timely manner. Given the known under-count of Māori within health and disability sector data,[[19]] ethnicity data auditing to ensure the collection of ethnicity data is aligned to best practice and the HISO 10001:2017 Ethnicity Data Protocols should also be undertaken.[[20]]

The BSP has made progress with 10.1% of CRC diagnoses in Aotearoa New Zealand being made via the screening programme in 2019.[[6]] However, the BSP initially failed Māori by privileging NZ Europeans in its approach to screening eligible age.[[8]] One of the National Screening Unit’s (NSU) criteria for a screening programme is that “the health care system will be capable of supporting all necessary elements of the screening pathway, including diagnosis, follow-up and programme evaluation”.[[21]] To ensure that Te Whatu Ora districts do have adequate resources, the BSP has target waiting times for symptomatic colonoscopies that districts must achieve to partake in the BSP. The current system of removing people off the waiting list is artificially deflating the number of colonoscopies required. This results in the proxy measure of capacity and waiting time targets being artificially achieved while the system further perpetuates inequalities. The BSP does not require Te Whatu Ora districts to achieve and publish the proportion of accepted referrals by ethnicity that result in colonoscopies being performed. We suggest that adding a target here, with consequences for non-performativity, could be a mechanism by which the BSP can support achieving equity for Māori. In addition, the inequities observed for Pasifika in this study also deserve increased investigation.

We have shown that Māori, Pasifika and Asian people are more likely to be removed from a colonoscopy waiting list compared to NZ Europeans. We suggest that this inequitable access may be one of the causes for the higher mortality rates seen for Māori and Pasifika people with CRC. We suggest changes to the referral system to improve access.