PIKKO is a care concept funded by the Innovation Fund of the Federal Joint Committee in Germany (Gemeinsamer Bundesausschuss, funding number 01NVF17011) which supplements oncological care with an additional counseling and information pathway [17]. Participating patients were interviewed multiple times as part of the evaluation of this care concept. The intervention modules, which were available to the patients during the pandemic containment strategies, were: (1) the advice and support provided by a patient navigator (PN), who was available by telephone and in person for all questions concerning the treatment pathway, social law related issues and additional services; (2) a service offered by the Saarland Cancer Society (SCS) consisting of courses (nutritional counseling, art and creative courses, exercise courses, lectures) as well as psychological and psycho-social counseling; (3) a web-based knowledge database (“My PIKKO”) with general and specific information about the respective cancer disease, social law-related information, and additional supporting feature (e.g. a medical dictionary or list of questions to prepare for visits to the doctor) which were quality assured and prepared for laypersons [18]. Patients who were offered the above mentioned PIKKO modules (intervention group, IG) were compared with patients who received treatment as usual (control group, CG). In 2017 PIKKO started with the CG, which was recruited from 1 Nov 2017 to 31 Oct 2018, and surveyed through 31 Oct 2019. The recruitment of IG started on 1 Nov 2018 and ended on 31 Mar 2020, which was exactly in the period of the first lockdown in Germany. Data for the IG were collected through 30 Sep 2020 [17]. The data collection of the CG was not affected by the COVID-19 lockdown, but that of the IG was.

But it was not only the surveys that were affected by the pandemic, but also the intervention itself. The use of PN and offers of the SCS was often linked to a visit to an on-site facility (clinic, practice, course rooms) and thus to movement in the public space. This can be a barrier for many cancer patients because they can no longer participate in the study due to external circumstances - such as lockdown strategies - or they do not want to participate due to their own fears. Fortunately, the PN could also be reached by telephone from the very beginning, so this was already a familiar alternative method of contact for the PIKKO patients. Beginning 30 Mar 2020, the SCS offered its psychological and psycho-social counseling during extended telephone hours and produced course videos to offer the content of the courses to patients online. Other SCS courses took place outdoors (Nordic Walking, QiGong). “My PIKKO” operated independent of location anyway. This meant that the entire intervention was still available.

This supplementary survey, which was not included in the original study design of PIKKO, examines the impact of the pandemic on patients and the use of the intervention modules. Only the IG data collection took place under lockdown conditions and only the IG used the intervention modules. Therefore, all participants in this supplementary survey were from the IG. Participants were already informed about data privacy as part of the PIKKO study (The ethics committee of medical association of the Saarland approved the study protocol on 2 Nov 2017; approval number 114/17. The informed consent by study participants is obtained in a written way.) and the supplementary survey participation was voluntary.

All participants of the supplementary survey met the inclusion criteria of the PIKKO study (age 18–90 years, diagnosis of any cancer disease, treatment by doctors from the Saarland, insured with one of the four statutory health insurance companies participating in this study) [17], were part of the IG and had completed at least one PIKKO baseline questionnaire.

In the present survey, we investigated two groups with a quasi experimental design. Group A was not affected (“affected” is related to participation in the PIKKO study) by the lockdown because the patients went through the PIKKO intervention as planned. The end of the PIKKO intervention or the voluntary exit from the PIKKO accompanying survey took place before the lockdown (16 Mar 2020). Group B was affected by the lockdown (in connection with participation in the PIKKO study). Part of the PIKKO intervention and/or survey was conducted during the lockdown, so the end of PIKKO was in or after the lockdown. Group B should still have regular contact (including face-to-face) with the PN, attend (on-site) courses or counseling sessions of the SCS, and complete surveys (which were mailed). All of these may require direct contact, which was limited by the pandemic containment strategies. In addition, as late participants in the PIKKO study, they are still more likely to be in active cancer treatment and are likely to be more frequent guests at medical facilities. Group assignment was not random; rather, but was determined by the timing of inclusion in the PIKKO study (Group A: early inclusion = already enrolled in PIKKO for an average of 358 days at the time of lockdown; Group B: late inclusion = already enrolled in PIKKO for an average of 167 days at the time of lockdown).

The supplementary survey took place from 31 July 2020 to 31 Aug 2020.

To assess the impact of pandemic containment strategies on our cancer patients, we asked them questions about four aspects: Restrictions (“Have you had any restrictions with regard to your disease since 16 Mar 2020?: Yes/No If yes, which?”), influence on disease (“Do you think that the limitations due to the COVID-19 pandemic have an influence on the course of your disease?: Yes/No”), use of PIKKO (“Did you use parts of the PIKKO intervention during the limitations due to the COVID-19 pandemic?”), and their own sense of burden (“8 sub-questions on stressful situations to the assessment of the burden of the restrictions (CBS)”).

Our self-designed COVID-19 conditional burden scale (CBS) questions covered the points of (1) hygienic strategies, (2) change of appointments, (3) movement in the public space, (4) cover mouth and nose, (5) no accompanying persons, (6) interaction with the medical staff, (7) interaction with the nursing staff, (8) ban on visits to the wards. Each of the questions could be rated on a 5-point Likert scale (0 = not stressful, 1 = a little stressful, 2 = moderately stressful, 3 = much stressful, 4 = very much stressful). Since not every patient was exposed to all eight stressful situations, the mean should be taken only for the questions answered, so missing (= item did not apply or was not ticked) enters the equation. The following formula was used to compute the CBS score (= the mean of all the patient’s responses): CBS-Score = Sum(CBS1, CBS2, CBS3, CBS4, CBS5, CBS6, CBS7, CBS8) / (8 – Sum(Missing)).

The score ranges from 0 (no load) to 4 (heavy load). Cronbachs Alpha for the cases where all 8 items were completed is 0.9 (N = 52).

Furthermore, previously collected utilization data from the main PIKKO study concerning the intervention modules were analyzed for the COVID-19 period.

The four questions concerning COVID-19 were collected using a two-page questionnaire.

From our regular patient survey [17], socio-demographic and disease data as well as the frequency of PN contacts was taken, retrospective during the last three months before the survey time. The SCS provided data on the use of psychological and psycho-social counseling and of the different courses (Nordic Walking, yoga, QiGong, nutrition, music therapy, art and creativity), which are presented on a monthly basis. A log file of the knowledge database “My PIKKO” allowed to count the monthly accesses of the patients. All frequencies are based on simple counts performed by the patients themselves (contacts to the PN), the SCS (use of their service) or automatically by the website.

Since the cancer patients interviewed were already part of the main PIKKO study, a selection bias can be assumed here.

A full survey of all living PIKKO-IG participants was intended (n = 503).

First, selection effects were investigated by comparing participating and non-participating patients in the supplementary survey. To examine the selection bias, chi-square tests and F-tests were performed (independent variable: patient included versus excluded, depended variables: age, sex, etc.). Next, we compared the both groups of survey participants (not affected, A, and affected, B, by lockdown with regard to PIKKO) regarding to socio-demographic data, disease data, and treatment as well, using chi-square tests and F-tests.

Then we compared both groups (not affected, A, and affected, B, by lockdown with regard to PIKKO) regarding health care related variables.

To examine the restrictions in relation to the disease we conducted chi-square tests.

To quantify the burden due to the pandemic containment strategies, we applied first a linear regression. All single items of the COVID-19 CBS and the sum score of the CBS (in separate calculations) were used as dependent variables. As independent variables we considered Group (0: not affacted, 1: affected), age (grouped by median, 0: under 60 years, 1: 60 + years), gender (0: female, 1: male), children in the household (0: no, 1: yes), financial burden (0: no, 1: yes), period of the most recent illness (dummy variable A: up to 1 year versus 6 + years, dummy variable B: 2–5 years versus 6 + years) and cancer treatment at baseline (dummy variable A: active treatment versus no active treatment, dummy variable B: only rehabilitation versus no active treatment). Based on the estimated regression coefficients we estimated adjusted group means and compared them with t-tests.

The assumption of an influence on the course of the disease and using of parts of the PIKKO intervention during the lockdown was investigated with chi-square tests.

Cramer-V [19] (V > 0.1: small effect; V > 0.3: medium effect; V > 0.5: strong effect) and partial Eta-squared [20] (η²>0.01: small effect; η²>0.06: medium effect; η²>0.14: strong effect) are used as effect sizes.

Missing values did not occur in the dichotomous questions. Missing answers in the CBS that occurred when an item/situation did not apply to the patient were marked as “not applicable” were included in the calculation of the CBS score as “8 - Sum(Missing)”. Only if all subitems were “not applicable”, these cases were excluded from the CBS analysis.

In all analyses, the level of significance was α = 0.05.

Data on the utilization of the PIKKO modules (Patient Navigator, SCS counseling and courses, knowledge database) were analyzed descriptively.