Surveys were completed by 100 physicians and 100 patients in each participating country, enabling a robust comparison between the two groups within each country. The physician response rate ranged from 4% to 11% across the countries, and the patient response rate ranged from 17% to 20%. The characteristics of participating physicians and patients are shown in Table 1. The majority of physicians were PCPs, except in Taiwan, where most physicians were endocrinologists. Approximately one-fifth of participating physicians in the Philippines were diabetologists.
The majority of patients in Hong Kong and Taiwan were male, whereas in the Philippines and Thailand the majority were female. The percentages were similar in Malaysia. In Hong Kong, Malaysia, and Thailand, the majority of patients were aged ≤45 years, but, in the Philippines and Taiwan, most were aged 46–65 years. In Hong Kong and Malaysia, the majority of patients had Type 1 diabetes, whereas in the Philippines, Taiwan, and Thailand, most patients had Type 2 diabetes. The mean duration of diabetes ranged from 5.5 to 10.2 years. The mean time between diabetes diagnosis and onset of pDPN ranged from 2.2 to 7.7 years, and the mean time between the onset of first painful neuropathic symptoms and presentation to a physician ranged from 1.0 to 2.4 years. Most patients reported the presence of at least one comorbid condition, the most common being hypertension.
Prevalence, Severity, and Impact of pDPN
Physicians in Hong Kong, Taiwan, and Thailand estimated the prevalence of pDPN to be 12–18%, while physicians in Malaysia and the Philippines estimated pDPN prevalence at 29% and 33%, respectively, similar to that reported in Western countries [4,5,6,7].
Most patients described their pain severity as mild or moderate, but 2–12% of patients described it as being so disabling that they were unable to perform daily tasks. Most patients experienced pain first in their feet (range 32–79%), followed by their legs (range 27–50%), and then fingers and/or toes (range 18–64%). Physicians’ stated that patients reported their pain occurring first in the feet (range 90–97%), followed by fingers and/or toes (51–77%), and then legs (42–60%).
There was a clear difference in patient and physician perspectives on the impact of pain (Fig. 1), but these were not consistent across countries. More physicians believed the patients’ pain had a serious to very serious impact on quality of life compared to the patients themselves. Patients reported that their pain had a greater impact on sleep, anxiety, depression, ability to perform exercise, and ability to carry out work than did the physicians.
Screening, Diagnosis, Treatment, and Monitoring of pDPN
The proportion of patients being screened for pDPN varied widely between countries (Fig. 2). The lower active screening rate was reflected in the low priority status assigned by physicians to the relief of pain from pDPN, particularly in Taiwan and Hong Kong (Fig. 3). Physicians considered glycemic control, maintenance of kidney function, and management of lipid disorders to be higher treatment priorities than relief of pain from pDPN.
Most physicians believed that pDPN requires a formal diagnosis (range across countries, 77–96%). Of the patients presenting with painful neuropathic symptoms, up to one-third (range 5–33%) received a formal diagnosis of pDPN at the initial meeting, with the majority receiving a diagnosis within 3 months. However, in some countries, approximately one-quarter of patients had to wait more than 6 months for a formal diagnosis of pDPN (Hong Kong = 26%; Malaysia = 23%; Thailand = 29%). Physicians and patients broadly agreed on the assessment parameters commonly used to diagnose pDPN. Clinical examination (physician-reported range, 34–96%; patient-reported range, 37–72%), symptom assessment (physician-reported range, 70–85%; patient-reported range, 42–77%), and medical history (physician-reported range, 62–95%; patient-reported range, 15–78%) were the most common parameters used. Other parameters that were used less frequently included foot examination, nerve conduction, and monofilament testing.
There was disparity between patient and physician reports on the specialties involved in the diagnosis and management of pDPN (Supplementary Fig. 1). Most physicians believed that PCPs were the most active in diagnosing pDPN (range across countries, 67–97%), whereas patients reported that PCPs provided the diagnosis less often (range 6–54%) (Supplementary Fig. 1A). By comparison, patients reported that endocrinologists or diabetologists were more likely to provide the diagnosis (range 21–72%), but physicians believed that an endocrinologist or diabetologist provided the diagnosis less often (range 2–23%). More physicians than patients believed that PCPs managed pDPN (ranges 27–65% and 1–49%, respectively), whereas patients believed that endocrinologists or diabetologists were more likely to manage pDPN compared with physicians (ranges 28–82% and 31–50%, respectively) (Supplementary Fig. 1B). Both groups agreed that other specialties, such as orthopedic surgeons and internists, were less commonly involved in the diagnosis and management of pDPN.
Physicians and patients believed that key barriers to treatment were patients’ lack of awareness of pDPN (ranges across countries, 64–83% and 38–68%, respectively), their fears over potential additional costs of treatment (ranges 30–79% and 40–74%, respectively), their difficulty or hesitation in describing their pain (ranges 29–48% and 24–46%, respectively), and limited consultation time (ranges 10–54% and 41–62%, respectively). Additionally, a relatively high proportion of patients did not think their pain was a serious condition (range 26–57%), and some believed that management of pDPN was unimportant compared with their other conditions (range 18–53%).
Physicians typically recommended changes in lifestyle, prescription medications, and tighter control of blood glucose levels to treat mild, moderate, and severe pain, irrespective of country. They also recommended vitamins and health supplements across all pain severities. Patients with mild and moderate pain responded that they were typically recommended changes in lifestyle, improved blood glucose control, vitamins and health supplements, as well as prescription medications. There were too few patients with severe pain to provide meaningful results.
The majority of patients reported that physicians started monitoring pDPN upon diagnosis (Fig. 4a). However, there was disparity between patients and physicians regarding the reported duration of monitoring (Fig. 4b, c). Typically, patients reported shorter durations of monitoring compared with the physicians.
Communication, Engagement, and Information on pDPN
Regarding the initiation of conversations about pDPN, both patients and physicians agreed that the patients were more proactive (Fig. 5). The only exception to this was physicians in the Philippines who believed that they were more likely to start the conversations compared with their patients. Patients regarded physicians as their primary source of information on pDPN (range across countries, 62–92%), followed by their families (23–64%), and friends or colleagues (9–43%). Pharmacists were not reported as a common source of information, with the exception of Malaysia (51%). Patients across the region rarely referred to the media, e.g., newspapers, books, or television, for information (range 0–3%).
Both physicians and patients believed that pain scales (range across countries, 59–81% and 43–80%, respectively) and local language descriptions for pDPN-related symptoms (range 52–81% and 50–82%, respectively) were the most useful tools in helping patients to describe their pain. When describing pDPN-related symptoms, “numbing sensation” was used by approximately 80% of patients across the region, with the exception of Hong Kong (33%). “Tingling pain” (range across countries 38–67%) and “pins and needles”-like feeling (range 43–89%) were also common terms. Individual countries used some terms more commonly than others, such as “sharp or stabbing” pain (65%) and “electric shocks” (54%) in the Philippines, and “burning sensation” in Malaysia (55%).
Physicians most commonly referred to guidelines from the American Diabetes Association (ADA)  (range across countries 37–87%) or local diabetes guidelines (range 43–90%) for diabetes management (Supplementary Fig. 2). They were generally aware of sections referring to the management of pDPN in the guidelines they used, especially in those from the ADA (range 26–74%) and local guidelines (range 16–75%). However, in Hong Kong and the Philippines, 41% and 22% of physicians, respectively, were not aware of any reference related to the management of pDPN in the guidelines they used.