Understanding healthcare demand and supply through causal loop diagrams and system archetypes: policy implications for kidney replacement therapy in Thailand | BMC Medicine

Our analysis highlighted three main dynamic interactions influencing demand and quality of care following the 2022 policy change: (1) shifts in quality of HD service provision caused by short-term coping mechanisms to deal with the surge in HD demand; (2) mechanisms to address workforce shortages that inadvertently exacerbated system strain; and (3) development of infrastructure for HD at the expense of the PD service system. In the following sections, we outline the causal relationships underlying each of these components, applying system archetypes to identify potential solutions. Feedback loops in the CLD are summarised in Table 3 and system archetypes with potential solutions in Table 4.

Coping measures to deal with the surge in demand for HD lowered quality standards and induced further HD demand

The 2022 policy change removed eligibility criteria determining which patients could be fully reimbursed for HD. As a result, there was a surge in demand for HD, placing pressure on vascular access services (required before patients can initiate HD) as well as HD centres. A series of short-term measures were taken by the public health insurance agency (NHSO), private HD centres, and doctors to cope with the increase in demand. However, as shown in Fig. 1a, certain key measures had unintended consequences that controlled the problem in the short term but exacerbated the supply constraints in the long term. These measures are characteristic of the out-of-control archetype (B1/R1, B2/R2, B3/R3, and B4/R4), in which a balancing loop is counteracted by a delayed reinforcing loop, and that of the relative-control archetype (drifting goal as a special case, B1/B2).

a Dynamics causing shifts in quality of HD service provision caused by short-term coping mechanisms to deal with the surge in HD demand. b Potential solutions (in pink) to address the problems in a, based on generic solutions for out-of-control and relative control archetypes. HD—haemodialysis, KPI—key performance indicator, QA—quality assurance

The first coping measure had been taken by NHSO prior to 2022. Regulations to approve a new HD centre were relaxed, allowing HD centres to provide services without Thailand Renal Replacement Therapy (TRT) certification (balancing loop B1), in order to accelerate approval of new HD centres given the limited capacity for quality assurance (QA).

“ปี 63 ยกเลิกใช้ใบ ตรต. ทำให้มีหลายที่ไม่ได้ขึ้นทะเบียนหน่วย และเข้า สปสช. ได้เลยในบางเขต ทำให้มีปัญหาในเทศบาล ที่จะตั้งเป็น รพ. ที่จัดตั้งไม่ได้ ไม่มีคนช่วยดูการขึ้นทะเบียน ถ้า outsource ไม่ยื่นตรวจ ตรต. ก็จบ”

“In 2020, the requirement for TRT certification was abolished, causing many centres to provide services to NHSO without TRT registration. [The TRT certificate] had been causing problems in certain municipalities that were setting up hospitals that could not be established as there was no one to facilitate the registration. If the centre manager did not submit a TRT registration report, it was over.”

Kidney Association representative (the Kidney Association is responsible for the management of TRT), workshop on 9 th July 2024

However, this policy unintentionally increased demand for HD: the opening of private HD clinics meant that more patients could access HD, putting pressure on NHSO to maintain the lower QA standards (reinforcing loop R1). Perhaps more importantly, B1 and B2 form a relative control archetype, in which actions to control the inadequate QA system distracted away from investment in QA capacity to regulate the growing number of HD centres. This illustrates the archetype of drifting goals (i.e., a special case of relative control archetype), in which targets are lowered for short-term impact instead of addressing the fundamental problem (inadequate QA capacity). In the longer term, this could lower the perceived importance of regulatory mechanisms (reinforcing loop R2), leading to chronic underinvestment in QA. This is a case of shifting the burden archetype, in which the short-term fix undermines fundamental solutions.

The second set of measures to address the surge in HD demand was taken by private HD centres. HD centres are reimbursed per HD session [47], creating a system in which the goal is to increase number of HD sessions per centre. To address the high demand for HD, certain private centres reduced the length of HD sessions and cut back on infection prevention and control measures (balancing loop B3). As a result, the rate of complications among HD patients increased. Although patients with complications receiving HD at public or private hospitals can be treated in the same hospital, patients in private HD clinics have to transfer to a hospital. High complication rates can therefore increase the number of transfers from private HD clinics to hospitals. Beyond increasing burden on hospitals, this reduces the number of clients in private HD clinics and increases competition for clients. Private HD centres can attract new patients by remunerating doctors referring patients to their HD centre. This fee (referred to as the doctor fee) is paid per patient per session. In the private centres surveyed, 3 out of 4 paid a doctor fee, which varied between 150 and 250 THB per session.

“ค่า DF เนี่ยมันเกิดขึ้นเนื่องจากว่าโรงพยาบาลหรือเอกชนเนี่ยไปออกแบบเองเพื่อที่จะดึงคนไข้แล้วก็อาจจะให้หมอโรคไตชักจูงให้หมอโรคไตส่งคนไข้เนี่ยไปให้เขา นึกออกไหมครับ ส่งคนไข้ไปให้เขาถ้ายิ่งส่งมาเขาก็จะมีค่าตอบแทนกลับไปของหน่วยบริการนะ”

“The DF [doctor fee] was designed by hospitals and private companies to attract patients and to persuade nephrologists to refer patients to them. Do you understand? If you refer patients to them, the more patients you send, the more compensation you will receive from the HD centre.”

Nephrologist 1 interview

Increased competition for HD patients can raise the doctor fee, increasing the financial benefit for doctors to recommend HD to their patients (or even to initiate HD prematurely), further increasing number of new HD patients and maintaining demand to increase HD supply (reinforcing loop R3). This is an example of setting the wrong goal archetype, in which the incentives in the system lead to agents following a goal that is not aligned with the broader health system objectives.

The final coping mechanism in this section concerns vascular access, which is required before patients can initiate HD. The surge in HD patients meant that there were long waiting times for vascular access. Many doctors therefore initiated patients on HD with temporary access (balancing loop B4). Although this temporarily relieved pressure on vascular access services, it is another example of the fixes that fail archetype (a special case of out-of-control archetype), in which a delayed reinforcing loop unintentionally exacerbates the problem, as HD patients with temporary access are more likely to need multiple vascular access operations, leading to a growth in demand for vascular access services over time (reinforcing loop R4).

“อย่างเช่นเส้นเลือดอย่างเช่นตรงอะไรอย่างเงี้ยมันก็ไม่ทันครับมันก็ไม่ทันเพราะมีการ shift พอสมควรเลยก็ต้องไปใช้เส้นเลือดชั่วคราวเยอะขึ้น”

“For example, things like blood vessels are not ready in time. It’s not in time and because there’s quite a lot of shifting, we have to use more temporary vessels.”

Nephrologist 1 interview

HD patients with temporary access have a higher rate of complications [48], leading to a net increase in the average doctor fee, due to previously described mechanisms (reinforcing loop R5).

“คนไข้ต้องไปใช้เส้นเลือดชั่วคราวนะครับซึ่งมันมีเสี่ยงมากเลย เสี่ยงต่อการติดเชื้อ”

“The patient has to use temporary blood vessels, which are very risky and risk infection.”

Nephrologist 1 interview

Policies to ensure adequate supply while maintaining quality of care

Our analysis of system archetypes identified the following policy interventions: (1) pre-authorisation of new HD patients that accounts for availability of vascular access and HD services, (2) key performance indicators (KPI) related to number and competence of QA staff in relation to number of HD centres, and (3) changing the payment mechanism from fee per service to quality-based payments per patient. Figure 1b depicts the potential impact of these policies on the causal loop diagram.

A pre-authorisation system would require each patient to be approved by an oversight board at the regional level before they are able to access dialysis services. A similar system had been in place prior to the 2022 policy change. However, unlike the 2008–2022 policy, the pre-authorisation system would allow patients who prefer HD to access HD, provided that (1) timing to initiate HD is appropriate given the patient’s kidney function, (2) the patient would not have better quality of life with another treatment, and (3) there is available HD supply. In the context of constrained HD supply, patients requesting HD who are not contraindicated would be required to start dialysis on PD. This solution aims to reduce induced demand for HD, including premature HD initiation, by replacing reinforcing loops R1/R6 and R5 with balancing loops B1a and B4b respectively. In balancing loop B1a, pre-authorisation phases the increase in HD patients at a rate that is constant with regulatory approval of new HD centres. In balancing loop B4b, excess demand for vascular access beyond system capacity is similarly moderated. This solution had already been proposed by the policy working group prior to our analysis.

The intention of a key performance indicator for QA staff would be to set a goal (for either the Ministry of Public Health or NHSO) that maintains investment into the QA system independent of measures to relax/heighten regulations. Such a measure aims to guard against a loss of capacity and maintain perceived importance of QA, by triggering investment when capacity is insufficient (balancing loop B2a).

Changing the payment mechanism from fee per session to patient-level payments contingent upon quality indicators aims to better align goals of service providers with those of the health system. Instead of increasing number of HD sessions, the emphasis is shifted to improving quality of patient outcomes. Reinforcing loop R3 is closed by balancing loops B3a and B3b, since higher complication rates trigger measures to improve quality of care (balancing loop B3a). This in turn reduces the funding available to pay for the doctor fee (balancing loop B3b). Patients with temporary access are expected to decrease also, in an effort to reduce complications (balancing loop B4a).

Mechanisms to address HD nurse shortages compromised quality of care and placed increased pressure on the HD nurse workforce

One of the factors counterbalancing the increase in HD supply is the availability of HD nurses, which acts as a limit to HD growth (loops R1/B5). As shown in Fig. 2a, the number of HD nurses can be increased through additional training, according to annual quotas determined by the Nursing Council. Short-term responses to overcome nurse shortages temporarily relieved system pressure, but compounded deficit of HD nurses in the long term, either by increasing demand for HD (out-of-control archetypes B8/R9 and B6/R8) or by decreasing number of HD nurses (out-of-control archetype B6/R7 and relative control archetype B6/B7).

a Dynamics affecting availability of HD nurses relative to demand. b Potential solutions (in pink) to address the problems in a, based on generic solutions for out-of-control and relative control archetypes. HD—haemodialysis, KPI—key performance indicator, PD—peritoneal dialysis

In the current system, HD nurses have opportunities for career progression and recognition that are not available to PD nurses. There is therefore an ongoing transition of PD nurses to HD, which tends to be the more experienced nurses.

“Career pathway ผลตอบแทนพิเศษ แรงจูงใจ ไม่มีให้พยาบาล PD”

“PD nurses do not have a career pathway, special compensation, or incentives.”

Nephrologist 1, workshop on 9^th July 2024

“Mindset คนไทยให้ของขวัญพยาบาลไตเทียมเยอะ มี social recognition”

“It is in the mindset of Thai people to give lots of gifts to haemodialysis nurses. They have social recognition.”

Nephrologist 2, workshop on 9 th July 2024

With the sharp increase in HD nurse deficit following the 2022 policy change, one of the system responses was an increase in the rate of PD nurses transitioning to HD (balancing loop B8), which had implications for patient decisions between PD and HD (reinforcing loop R9). One of the main factors influencing patient decisions between PD and HD is perceived risk of infection on PD:

“[The three patient representatives] mentioned that they may not fully understand the concept of quality or survival outcomes, but they focus on the side effects and complications of dialysis, such as infections […] Complications seem to be one of the main factors that concern some patients.”

Observations of patient inputs, workshop on 9 th July 2024

Although there are complications for HD too, the symptoms are often difficult to attribute directly to HD (for example, sepsis or cardiovascular disease), whereas the cause of peritonitis and other PD complications is less ambiguous.

As more PD nurses switch to HD, risk of infection for PD patients increases due to the higher ratio of PD patients per nurse [49] and loss of experienced PD nurses.

“More experienced nurses tend to move to the private sector. The government setting has to train new, less experienced nurses, which may affect the quality of service.”

Observations of nurse inputs, workshop on 9 th July 2024

As a consequence, the proportion of PD-eligible patients choosing HD increases. This is another example of the out-of-control archetype, as the short-term counteracting measure exacerbates demand for HD nurses in the long term. Although PD nurses switching to HD is not an intentional action (which is a common feature of archetypes), we have nonetheless included it within the CLD, as it is influenced by the compensation and professional hierarchy within the Ministry of Public Health system.

The second mechanism to control the deficit in HD nurses was implemented by HD centres. HD nurse training takes 4–6 months (or longer for specialised HD nurses), represented by the delay in balancing loop B7. Many centres therefore implemented short-term measures to address workforce shortages (balancing loop B6): more HD nurses worked overtime or extended their hours to cover more shifts and some private HD centres registered the same nurse in two centres with overlapping shift times. As a result, more HD nurses had high workload, experienced burnout, and left to other professions (reinforcing loop R7).

“The increase in salary is not due to the amount of money but because of the increased workload (number of sessions and patients). This causes the number of nurses to decrease because it affects their quality of life.”

Observations from public sector nurse input, workshop on 9 th July 2024

Short-term coping mechanisms not only distracted away from HD nurse training programmes (relative control archetype, B6/B7), but also reduced training programme impact, as HD nurse turnover had increased (out-of-control archetype, B6/R7). Quality of HD services also decreased. Similar to reinforcing loop 3, this can lead to an increase in financial incentives for HD, exacerbating HD nurse shortages in the long term (reinforcing loop R8).

Policies to sustainably address shortages in HD nurse workforce

We identified the following potential solutions to the deficit in HD nurses, based on the system archetypes: (1) quality-based payments per patient as opposed to payment per HD session, (2) setting a KPI for the Ministry of Public Health or the Nursing Council related to number of registered HD nurses relative to HD patients, and (3) enforceable regulations defining maximum HD patients and/or hours per HD nurse. The modified CLD with solution archetypes is shown in Fig. 2b.

Quality-based payments per patient aim to change the incentive for healthcare providers towards increasing patient quality of life. This closes reinforcing loop R8, as it is expected that HD centres are more likely to adhere to the recommended number of nurses per patient, in order to manage complication rates (balancing loop B8a).

Setting a KPI for the HD nurse to patient ratio aims to fix number of nurses trained according to actual need (nurse to patient ratio) and not perceived need, which may be obscured by temporary coping mechanisms. This provides a holistic solution to the relative control archetype in loops B6, B7, and B8, as the fundamental solution to HD nurse shortages (training) is moderated relative to KPI performance (B7a and B9). This KPI is not at the level of individual centres (who face severe nurse shortages) but at the national level. It would require, however, regular censoring of HD nurses in active employment, which does not currently exist, and measures to address regional health workforce inequities.

Enforceable regulations around maximum workload for HD nurses (in terms of patients and/or hours per week) aim to reduce burnout of HD nurses. The structure of loop R7 is changed to a balancing loop (B6a), controlling HD nurse burnout by punishing HD centres exceeding the permissible weekly HD nurse workload.

Underinvestment in PD capacity coupled with increasing investment in HD has led to a decline in PD uptake

In contrast to the HD system, the system for PD is characterised by archetypes that limit its growth (Fig. 3a).

a Dynamics affecting availability and quality of PD services. b Potential solutions (in pink) to address the problems in a, based on generic solutions for underachievement and relative achievement archetypes. HD—haemodialysis, PD—peritoneal dialysis

In the growth and underinvestment archetype (special case of the underachievement archetype), an initial improvement in performance is limited by a resource constraint, and the resulting drop in performance discourages further investment [19]. In the case of PD, as number of PD patients increases, so does experience and size of PD centres, improving the quality of PD services [49, 50] (reinforcing loop R10). However, quality is also dependent on the availability of PD nurses [49, 50], which decreases with more PD patients (balancing loop B9). Expansion of PD capacity (including number of PD centres and PD nurses) is dependent on perceived investment need by hospital directors. There is a delay between perceived investment need, investment, and increase in capacity, due to the time to train nurses and open PD centres (balancing loop B10). As a result, increases in infection from lack of capacity can lead to fewer patients choosing PD, which disincentivises further PD investment.

“If the number of PD patients decreases, hospital directors may not perceive the importance of PD nurses and may not support their training.”

Observations from nephrologist input, workshop on 9^th July 2024

The second archetype constraining growth of PD is the success to the successful, or relative achievement archetype. In reinforcing loop 9, an increase in PD nurses switching to HD led to fewer patients selecting PD. When combined with reinforcing loop R10, this leads to a loss in the experience and culture of PD in public hospitals providing PD services. The growth of HD is therefore achieved at the expense of the PD system.

Policies to maintain capacity for PD

The solution archetype for underachievement involves development of a proactive plan, and the solution archetype for relative achievement entails external regulation [19]. As shown in Fig. 3b, proactive planning to scale PD investment relative to projected PD demand addresses underinvestment in PD (reinforcing loop R10a), while an independent pre-authorisation system to approve patients initiating HD according to patient characteristics would maintain the number of patients selecting HD at a level that is sustainable for the system (reinforcing loop R9a).