We assess the number and severity of chronic diseases using a modified version of a self-report instrument developed by Bayliss et al. (2005). The original questionnaire includes a list of 23 common chronic conditions. Validation against the standard criterion of medical record review showed a mean sensitivity of 75% and a mean specificity of 92%. For our study, the specificity of the original scale was reduced by grouping similar disorders together. Two additional comorbidities were added: mental disorders and sensory disturbances. The modified questionnaire contained a final 18 conditions: hypertension, asthma, lung disease, diabetes, thyroid disease, chronic back pain, rheumatism, osteoarthritis, osteoporosis, colon problems, stomach problems, kidney disease, sensory disturbances, heart disease, stroke, neurological disease, eye disorders, and mental disorders. For each condition, respondents indicate whether they currently have the condition and whether the condition affects their daily activities from 1 (“not at all”) to 5 (“very much”). A comorbidity index can be calculated, which represents the degree of morbidity. The total score ranges from 0 to 90 and represents the sum of the conditions weighted by the degree of impairment assigned to each condition (Bayliss et al., 2009).

We use the Karnofsky Performance Status Scale (KPS) (Karnofsky and Burchenal, 1949) to rate the ability of a patient to perform usual activities. A person is evaluated on a score ranging from 0 to 100, where 0 is “dead” and 100 is “normal, no complaints, and no signs of disease.” The lower the Karnofsky score, the worse the survival for most severe diseases such as cancer.

The Structured Clinical Interview for DSM-5 Disorders – Clinical Version (SCID-5-CV) (First et al., 2015) is a semi-structured interview for diagnosing mental disorders according to the DSM-5. Each DSM-5 criterion is assigned corresponding interview questions to assist the interviewer in assessing the criterion. The interview covers the most common DSM-5 diagnoses encountered in the clinical setting. In this study, 7 of the 10 modules were asked: (i) mood episodes and persistent depressive disorder, (ii) differential diagnosis of mood disorders, (iii) substance use disorders, (iv) anxiety disorders, (v) obsessive-compulsive and related disorders and posttraumatic stress disorder (PTSD), (vi) screening questions for other disorders, and (vii) adjustment disorders.

We measure psychological distress by using the validated German version of the Distress Thermometer (DT) (Roth et al., 1998; Mehnert et al., 2006b). The DT is a valid, reliable, and widely used screening measure. The screening contains a single−item visual analog scale ranging from 0 (“no distress”) to 10 (“extreme distress”) to quantify the global level of distress experienced in the past week including the current day and a standardized problem checklist containing 36 potential causes of distress (yes/no questions) that are grouped into 5 categories including physical problems (21 items), practical (5), family (2), emotional problems (6), and spiritual/religious concerns (2). A score of ≥5 at the visual analog scale is recommended as a cutoff for a clinically significant level of distress (Mehnert et al., 2006b; Donovan et al., 2014).

We measure emotional responses beyond core distress during the past week, including the current day using the validated German version of the Emotion Thermometers (ET) as a multi-domain screening (Mitchell et al., 2010a,b; Hinz et al., 2019). In addition to the general distress screening, the ET consist of four visual analog scales that measure anxiety (AnxT), depression (DepT), anger (AngT), and the need for help (HelpT). Similar to the DT, all dimensions are to be rated on the visual analog scale with the anchors 0 (“none”) and 10 (“extreme”). Higher scores indicate higher emotional distress or need for help.

We additionally assess the current burden of the COVID-19 pandemic using a 5-point Likert scale ranging from 1 (“not distressed at all”) to 5 (“highly distressed”).

We use the validated German version of the Patient Health Questionnaire Depression Module (PHQ-9) (Kroenke et al., 2001; Löwe et al., 2004), the 9-item depression module from the Patient Health Questionnaire (PHQ). It was designed to score each of the DSM-IV (Bell, 1994) criteria of major depression on a 4-point Likert scale from 0 (“not at all”) to 3 (“nearly every day”) over the previous 2 weeks. The PHQ-9 is recommended by the DSM-5 working group of the American Psychiatric Association as an instrument to measure the severity of major depression according to the new DSM-5 criteria. The total score ranges from 0 to 27. The PHQ-9 has excellent reliability, as well as criterion, construct, factorial, and procedural validity (Löwe et al., 2004). A score up to 4 indicates the absence of depression, scores of 5–9 represent mild, scores of 10–14 represent moderate and scores of 15 and higher represent severe depression (Löwe et al., 2004). For the German general population, normative data for the PHQ-9 are available for both genders and different age groups (Kocalevent et al., 2013).

We use the validated German version of the Generalized Anxiety Disorder Scale (GAD-7) (Spitzer et al., 2006; Löwe et al., 2008), the 7-item generalized anxiety module from the PHQ. The GAD-7 is based on the most prominent diagnostic features of the DSM-IV diagnostic criteria for generalized anxiety disorder and has excellent reliability, as well as criterion, construct, factorial, and procedural validity. The 7 items assess frequency of core generalized anxiety disorder symptoms within the past 2 weeks. Items are scored on a 4-point Likert scale ranging from 0 (“not at all”) to 3 (“nearly every day”) with a total score ranging from 0 to 21. A score up to 4 indicates the absence of generalized anxiety disorder, scores of 5–9 represent mild, scores of 10–14 represent moderate and scores of 15 and higher represent severe anxiety symptom levels (Löwe et al., 2008). For the German general population, normative data for the GAD-7 are available for both genders and different age groups (Hinz et al., 2017).

We use the validated German short form of the Fear of Progression Questionnaire (FoP-Q-SF) (Mehnert et al., 2006a) to measure fear of cancer progression and recurrence in patients and relatives (Zimmermann et al., 2011). The 12-item measure is based on the Fear of Progression Questionnaire (FoP-Q) (Herschbach et al., 2005). The FoP-Q-SF encompasses affective reactions, partnership/family, work, loss of autonomy and coping reactions and has a high internal consistency (α = 0.87). The FoP-Q-SF items are scored on a 5-point Likert Scale ranging from 1 (“never”) to 5 (“very often”). The total FoP-Q-SF score ranges from 12 to 60 and a score of 34 and above indicates a clinical level of FoP (Herschbach et al., 2010). Higher values indicate higher levels of fear of progression.

We measure cancer related quality of life (QoL) using the validated German version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC-QLQ-C30) (Aaronson et al., 1993; Schwarz and Hinz, 2001). This instrument is widely used and has excellent reliability and validity. The EORTC-QLQ-C30 contains 30 items, 28 of which are rated on a 4-point Likert scale that ranges from 1 (“not at all”) to 4 (“very much”) and clustered to 5 functioning scales (physical, role, social, cognitive, and emotional functioning); and 3 symptom subscales (fatigue, pain, and nausea and vomiting) and 6 single symptom items (dyspnea, sleeping problems, loss of appetite, constipation, diarrhea, and financial problems). General health and global QoL are rated on 2-items with a 7-point Likert scale that ranges from 1 (“very poor”) to 7 (“excellent”). The raw values are transformed into a range of values from 0 to 100. Higher scores in the functional subscales and global QoL subscale represent better functioning, whereas higher scores in symptom subscales and items reflect a greater extent of symptom distress and worse QoL. For the German general population, normative data for the EORTC-QLQ-C30 are available for both genders and different age groups (Schwarz and Hinz, 2001).

We use the validated German version of the Short-Form Health Survey (SF-8) to measure general health-related QoL (Ware et al., 1999), a questionnaire which was originally a short-form health survey with 36 questions. The SF-8 comprises eight dimensions of QoL: general health (GH), physical functioning (PF), role physical (RP), bodily pain (BP), vitality (VT), social functioning (SF), mental health (MH), role emotional (RE), and two summary scores for physical (PCS) and mental health (MCS). Items are rated on 5-point and 6-point scales. The raw values are transformed into a range of values from 0 to 100. Higher scores indicate better health-related QoL. For the German general population, normative data for the SF-8 are available for both genders and different age groups (Ellert et al., 2005).

To measure positive support and detrimental social interaction we use the short validated German version (ISSS-8) (Ullrich and Mehnert, 2010) of the Illness-specific Social Support Scale (ISSS) originally developed by Revenson and Schiaffino (1990) and adapted to German language by Ramm and Hasenbring (2003). The validated ISSS-8 captures social interactions perceived as positive and supportive (4 items) or as distressing or harmful (4 items). Items are scored on a 5-point Likert scale ranging from 0 (“never”) to 4 (“always”). Internal consistencies are satisfying to very good (Ullrich and Mehnert, 2010). Higher sum scores in both subscales indicate higher characteristic values.

We use the validated Dyadic Coping Inventory (DCI) (Bodenmann, 2008; Ledermann et al., 2010), a 37-item self-reporting instrument designed to measure perceived communication and dyadic coping (support each other, cope together and delegate stress to each other in times of overload) that occurs in close relationships when one or both partners are stressed. All Items are rated on a 5-point Likert scale that ranges from 1 (“very rarely”) to 5 (“very often”). The total DCI score is a sum of items 1 through 35. Items 36 and 37 are evaluation items and not included in this study. A DCI total score <111 represents a dyadic coping below average; DCI between 111–145 a dyadic coping in the normal range and a DCI total score >145 a dyadic coping above average. The evaluation of the German translation of the scale provide evidence of internal consistency for the overall scale (α = 0.91) and the individual subscales (German α range 0.61–0.86) (Bodenmann, 2008; Ledermann et al., 2010).

We use the validated German version of the Quality of Marriage Index (QMI) (Norton, 1983; Zimmermann et al., 2019), a brief self-report instrument, to measure global perceptions of relationship satisfaction. The scale consists of six positively worded items. Five items are rated on a 7-point Likert scale, ranging from 1 (“strong disagreement”) to 7 (“strong agreement”). The final item, a general estimation of the relationship satisfaction, is rated on a 10-point Likert scale, ranging from 1 (“very unhappy”) to 10 (“very happy”). Total scores range from 6 to 45, with higher scores reflecting better overall marital quality. The cutoff score is 34. The German QMI demonstrates good item characteristics and excellent reliability (α = 0.94) (Zimmermann et al., 2019).

To measures perceived feelings of loneliness and social isolation, we use the validated 3-item short version of the Loneliness Scale (LS-3) (Hughes et al., 2004), developed from the revised UCLA Loneliness Scale (Russell et al., 1980). In the German adaptation used in this study, items are scored on a 5-point Likert scale from 0 (“never”) to 4 (“very often”). A higher sum score indicates higher feelings of loneliness.

We use the validated German 12 item short version of the New Sexual Satisfaction Scale (NSSS-SD) (Stulhofer et al., 2010; Hoy et al., 2019), a widely used questionnaire for assessing sexual satisfaction. The questionnaire is originally based on two subscales (ego-centered and partner- and sexual activity-centered sexual satisfaction). For the NSSS-SD a one-dimensional factor structure was confirmed with excellent reliability (α = 0.96) (Hoy et al., 2019). This NSSS-SD measures satisfaction with various aspects of one’s own sexual life. The items are scored on a 5-point Likert scale from 1 (“not at all satisfied”) to 5 (“very satisfied”). The scores of all items are summed up. Higher scores indicate higher sexual satisfaction.

We use the Sexual Quality of Life (SQoL) questionnaire to measure quality of sexual life. The 18-item questionnaire captures sexual self-esteem, emotional wellbeing and relationship issues in women (SQoL-F) (Symonds et al., 2005) and men (SQoL-M) (Abraham et al., 2008). In the present study, the 18 items are used in a binary (male/female) form. Each item is rated on a 6-point Likert scale (“completely agree” to “completely disagree”) either in descending order 6 to 1 (items 1, 5, 9, 13, and 18) or ascending order 1 to 6 (remaining items). The values of the items are added to a sum score, which is then transferred to a standardized scale from 0 to 100. A higher score indicates higher SQoL (Symonds et al., 2005).

We use an adapted form of the German version of the Short-form Supportive Care Needs Survey (SCNS-SF34-G) (Sanson-Fisher et al., 2000; Lehmann et al., 2012). The single items cover the five dimensions of the original SCNS-SF34 (psychological support needs, support needs regarding physical problems and coping with daily living, support needs with regard to the health system and information, support needs with regard to patient care and support, and sexuality needs). Items are scored on a 4-point scale from 1 (“no need”) to 4 (“high need”). Higher scores indicate higher supportive care needs.

To assess patients’ perceived supportive care needs, we use single items that had proven suitable in earlier studies (Mehnert and Koch, 2008; Faller et al., 2016). To determine the need for psychosocial support, we ask participants, “Do you have a need for psychosocial support?” Response options were “yes” or “no.” We further ask participants “Would you accept an offer of psychosocial support?” with a yes/no response format to determine the acceptance of psychosocial support offers. In addition, we ask participants to rate the strength of their wish for talking (a) with clinical psychologist and (b) with a closely person: “Do you currently have the wish to talk about the psychological distress because of your cancer?” with the response options 1 (“not at all”), 2 (“somewhat”), 3 (“quite a bit”), 4 (“strongly”), and 5 (“very strongly”).

We ask the participants to rate the possibility of talking (a) with a psycho-oncologist and (b) with a close person: “Do you currently have the possibility to talk about the psychological distress because of your cancer?” with the response options 1 (“not at all”), 2 (“somewhat”), 3 (“quite”), 4 (“strongly”), and 5 (“very strongly”).

Using a 5-point response format ranging from 1 (“not at all”) to 5 (“very well”), we ask participants to evaluate their opportunities of talking about their distress to different persons, including family, friends, physicians, nurses, and psycho-oncologist. We ask patients “How well would you be able to talk to the below-mentioned persons about the psychological distress because of your cancer and cancer treatment?” with response options 1 (“not at all”), 2 (“somewhat”), 3 (“partly”), 4 (“well”), and 5 (“very well”), to be rated for each of the individual persons as indicated above.

To assess patients’ utilization of psychosocial support services, we ask participants “Have you previously utilized psychosocial support offers because of your cancer?” Six items further specified support: “psychological counseling/psychotherapy,” “social legal counseling,” “pastoral care,” “self-help groups,” “web based-support offers,” and “other offers.” Response options were “yes” or “no.” We further ask participants to rate how helpful they perceived the services to be when they had used them with the response options 1 (“not at all”), 2 (“rarely”), 3 (“somewhat”), 4 (“quite”), and 5 (“strongly”). We further asked utilization of cancer rehabilitation offers. Response options were “yes” or “no.”

We further ask participants if they had been advised by their partner or a close person to seek professional psychosocial support. Response options were “yes” or “no.” We further ask participants if they had received a recommendation from their doctor to seek professional psychosocial support. Response options were “yes” or “no.” We ask participants to specify which professional group was recommended to them (clinical psychology, social worker, pastor, and other). We also ask participants to indicate where they had sought professional psychosocial support (hospital, rehabilitation clinic, outpatient psychotherapy, outpatient cancer counseling center, and other). If participants had not sought professional psychosocial support, they were asked to indicate the reasons why they had not done so.

We ask participants to rate their attitude toward professional psychosocial support offers due to cancer on a numerical rating scale ranging from 0 (“negative”) to 10 (“positive”).

We use an adapted version of the validated German Satisfaction with Comprehensive Cancer Care (SCCC) Questionnaire (Esser et al., 2021) to measure satisfaction with medical and psychosocial cancer care. In detail, 32 items address human quality of physicians (interest of physicians toward patient and in his/her psychosocial condition), information (psychosocial support services/alternative possibilities of treatment and their consequences) and accessibility to psychosocial services (psychosocial counseling on supportive care services/psycho-oncological support/legal and financial advice/pastoral support/support in searching for a psychotherapist/support in acquiring coping strategies/support to join self-help or therapeutic groups). Response categories differ between item categories including 1 (“very dissatisfied”) to 5 (“very satisfied”); 1 (“very bad”) to 5 (“excellent”); and 1 (“do not agree at all”) to 5 (“completely agree”). Some items contain the additional response option 0 (“not applicable”). Higher values indicate higher satisfaction.

We measure health literacy using the validated German version of the European Health Literacy Survey Questionnaire (HLS-EU-Q16) (Röthlin et al., 2013), the 16-item short version of the 47-item European Health Literacy Survey Questionnaire (HLS-EU Consortium, 2012). The validated questionnaire has a high internal consistency (Cronbach’s alpha = 0.90). All items are rated on a 4-point Likert scale 1 (“very simple” to 4 (“very difficult”). The answer categories of all items are dichotomized. Answers 1 (“very simple”) and 2 (“fairly simple”) are scored with 0. Answers 3 (“quite difficult”) and 4 (“very difficult”) are scored with 1. The scores are summed up. A sum score ≤8 indicates “insufficient,” 9–12 “problematic,” and ≥13 “sufficient” health literacy.

We use the validated German version of the Adherence Assessment Questionnaire (AAQ) (Mueller et al., 2018), a self-reporting instrument to assess the extent of non-adherence in chronic indications. The 11-item AAQ has excellent reliability (α = 0.84 to α = 0.97) as well as a good validity. Eight items are formulated as statements that are rated on a 4-point Likert-scale from 1 (“strongly agree”) to 4 (“strongly disagree”). One additional item is stated as a visual analog scale to show the percentage of adherent days in the last 2 weeks. Moreover, two items measuring a patient’s tendency to answer in a socially desirable way were added to the AAQ. The scores of all items are summed up. Higher scores indicate higher inflexibility and less adherence.

Patients are asked about their drinking and smoking habits, physical exercise, relaxation techniques, regular intake of medication as well as weight and height for calculating the body mass index (BMI). The questions are adapted from the validated German Questionnaire for the Assessment of Health Behavior (FEG) (Dlugosch and Krieger, 1995) and the report of the Federal Health Monitoring in Germany (Schulze and Lampert, 2006). Items are rated on a 4-point Likert scales from 1 (“never”) to 4 (“daily”) or with the response options “yes” or “no.”

We use the validated German version of the Stigma Impact Scale (SIS) (Fife and Wright, 2000; Eichhorn et al., 2015) to measure perceived experiences of stigmatization. The 24-items measure the effect on patients and their families of negative social attitudes toward the patients’ health or mental health condition. The SIS consists of four subscales: social rejection (9 items), financial insecurity (3 items), internalized shame (5 items), and social isolation (7 items). All items are rated on a 4-point Likert scale that ranges from 0 (“do not agree at all”) to 3 (“fully agree”). Scale means and a total mean score can be calculated. The SIS has a high internal consistency (α = 0.81 to α = 0.89).

We use the validated German language Schedule for Meaning in Life Evaluation (SMiLE) questionnaire to measure meaning in life (Fegg et al., 2008). The SMiLE uses an idiographic approach and allows individuals to choose the life areas that they consider to be important for their own meaning in life. Respondents are first asked to indicate from 3 to 7 areas that actually provide meaning to their lives. In a second step (level of importance), the importance of each area is rated on a 5-point scale, ranging from 1 (“somewhat important”) to 5 (“extremely important”). In a third step (level of satisfaction), the respondents rate their current level of satisfaction with each area on a 7-point Likert scale, ranging from −3 (“very unsatisfied”) to +3 (“very satisfied”). Different indices can be formed, which indicate both the mean weighting of the meaning in life areas and the average satisfaction or dissatisfaction with the individual meaning in life areas.

We use the validated German version of the Life Attitude Profile-Revised (LAP-R) (Reker, 1992; Mehnert et al., 2007), a questionnaire assessing meaning and purpose in life and motivation to find meaning and purpose in life. Here, we use 20 items of the original 48-item questionnaire covering 6 dimensions: purpose (PU), coherence dimension (CO), choice/responsibleness (CR), existential vacuum (EV), and goal seeking (GS). The dimensions of the German validation have satisfactory to high internal consistencies (Cronbach’s alpha between 0.78 and 0.85). All items are rated on a 7-point Likert scale from 1 (“strongly disagree”) to 7 (“strongly agree”). Higher sum scores indicate higher characteristic values in each subscale.