From April 12 to May 13, 2019, 300 patients who fulfilled the inclusion criteria and were willing to participate were included in the study; 50 patients were recruited per target disease (Fig. 1).
The demographic and disease characteristics of the study population are presented in Table 1. While mean age was generally consistent across the diseases (ranging from 44.7 years (95%CI 41.4–48.0) for patients with CD to 50.8 years (95%CI 46.5–55.0) for patients with PsO), some sociodemographic and clinical characteristics were different between the disease populations. The great majority of patients with rheumatologic diseases and CD were women (90% of patients with RA, 88% with AS, 82% with PsA, and 82% with CD), compared to 58% of patients with UC and 68% with PsO (p < 0.05). Almost half the overall population were overweight or obese with BMI also varying across diseases: the majority of patients with PsO (54%), RA (60%) and PsA (66%) were overweight or obese compared to patients with IBD (38% of patients with CD and 34% of UC) (p < 0.05).
Age at diagnosis and mean time since diagnosis varied widely across diseases. The mean duration of illness was longest for patients with PsO and they were diagnosed at a younger age than patients with IBD and rheumatic diseases which were diagnosed more recently at a more advanced age. At least four of 10 patients declared having another chronic disease, ranging from 22% of patients with RA to 66% of patients with AS (p < 0.05). In 38% of the cases, the other chronic disease reported was another IMID: PsO and AS were reported in 13 patients (10%), CD in 11 patients (8%), asthma and fibromyalgia both in 8 patients (6%), PsA in 7 patients (5%), and multiple sclerosis in 5 patients (4%). Regardless of the disease, more than three quarters of patients reported complications since the time of their diagnosis of their IMID. Complications were different across diseases, but depression and overweight were reported by approximately four of 10 and more than a quarter of all patients, respectively.
At the time of their inclusion in the study, 93% of all patients were monitored by an HCP. While at least 90% of patients with rheumatologic diseases received care from a rheumatologist (94% with RA, 94% with AS and 92% with PsA) and more than 85% of patients with IBD from a gastroenterologist (94% with CD and 86% with UC), both mainly at a hospital or in a clinic, only 56% of patients with PsO were monitored by a dermatologist and 24% by a general practitioner, mainly in private practice (74%). Noteworthy, 22% of patients with PsO and 12% of patients with UC were not currently under the care of an HCP. Patients with PsA declared attending a hospital or clinic in 56% of the cases.
Patients’ perception of their level of control of their disease varied across disease groups and within a group (Table 1).
Lower level of control was observed for patients with PsA (4.2/10 95%CI 3.4–5.0), AS (4.5/10 95%CI 3.8–5.1) and PsO (4.8/10 95%CI 4.0–5.5). Patients with CD reported a better control of their disease (6.1/10 95%CI 5.4–6.8) (p < 0.05) (Fig. 2).
Throughout their care history, more than half of all patients (56%) were given some nutritional advice, mostly by the HCP monitoring their disease (36%) or another HCP (42%). Some patients reported having received recommendations from other patients or the Internet (25%), but very few received information from patient organizations (5%). The type of recommendations varied by the disease (Table 2). The diets recommended for patients with rheumatic diseases varied according to the disease; patients with AS were mainly advised to consume a gluten-free (32%) diet, different diets were recommended to patients with RA and PsA. Low-salt, low-calorie, low-sugar or gluten-free diets were recommended to 38, 30, 26 and 24% of patients with RA, respectively. Patients with PsA were advised to reduce their sugar (26%) and salt (20%) intake or eat a gluten-free (20%) diet. Patients with IBD were more frequently advised to have a low-fiber (58% of patients with CD and 42% with UC), low-salt (34% of patients with CD and 32% with UC) or gluten-free (32% of patients with CD and 32% with UC) diet. Patients with PsO declared having received little advice on nutrition (Table 2). Type of recommendation also varied by patients’ BMI: reducing calorie and sugar intake was frequently advised to overweight patients (62 and 57%, respectively, compared to 38 and 43% for underweight or normal weight patients).
Change in dietary habits
Since diagnosis, more IBD patients stated they changed their eating habits (80% of patients with CD and 60% with UC) compared to the other patients (42% of patients with RA, 32% with AS, 28% with PsA, and 20% with PsO) (p = 0.1) (Table 3). Regardless of the disease, this change was initiated more frequently by the patient than by their HCP (69% vs 31% overall). Of the 169 respondents who did not change their eating habits after initial diagnosis, 69% did not receive nutritional advice from their HCP. Of the patients with rheumatic diseases (50% of patients with RA, 36% with AS and 28% with PsA) and IBD (32% of patients with CD and 34% with UC) who received nutritional advice from their HCPs, between 14 and 69% followed this advice (69% of patients with CD, 59% with UC, 52% with RA, 44% with AS, and 14% with PsA). Only 8 of 50 patients with PsO were recommended specific diets and 2 of them applied them (Table 3).
Impact of diet change
Two thirds of the patients (66%) who had modified their diet experienced a change as a consequence. Even though positive consequences including weight loss, better physical fitness and improved mental health were observed by 27, 27 and 13% of patients, some negative consequences were reported such as increased fatigue (21%), disturbed sleep (15%) and difficulty carrying out normal physical activities (14%). The perceived consequences of the change in diet varied across the diseases. Patients with rheumatic diseases reported weight loss (44% of patients with AS, 33% with RA, and 21% with PsA) and better physical fitness (36% of patients with PsA, 29% with RA, and 25% with AS) but 24% of those with RA also mentioned increased fatigue. While 43% of patients with UC declared having better physical fitness and few negative effects (13% of all UC cases), patients with CD mentioned increased tiredness (43%), disturbed sleep (28%) and difficulty carrying out normal physical activities (28%). Noteworthy, one of five patients with CD reported feeling their nutritional intake was insufficient. Patients with PsO reported, beyond weight loss (50%), better physical activity (30%), improved mental health (30%) and reduced stress (20%), but no negative consequences. A non-negligible proportion of all patients stated they did not feel the change in their diet produced any consequences (25–38% of patients) (Table 4).
Nutrition services and informational materials
Overall, 24% of the patients were offered informational materials or services on nutrition. This varied depending on the diseases: 16% with rheumatic diseases (8% for PsA, 16% for AS and 24% for RA patients), 40% of patients with IBD (40% for both patients with CD and UC), and 10% with PsO (p < 0.05). They were mainly offered brochures (29%) or referral to nutritionist services (28%). Overall, patients were slightly dissatisfied with the information and/or services provided (overall median score = 4.5/10, with 10 = totally satisfied; Q1-Q3:2.5–6.0). Median satisfaction scores varied across diseases from 2.5 (Q1-Q3:2.5–5.5) for AS to 4.8 for CD (Q1-Q3:3.1–6.0) to UC (Q1-Q3:2.0–6.4) patients. Patients who had changed their eating habits as per the advice of HCP tended to be more satisfied with nutrition services and informational materials (mean score = 5.8 (95%: 4.6–6.9)) than those who self-imposed their diet (mean score = 3.8 (95%: 2.8–4.8)).