Table 1.
Cross-sectional Studies of Symptom Clusters in Heterogeneous Samples of Oncology Patients
| Author, Year, Title, Purpose, and Design | Sample Size, Patient Characteristics, Time of Symptom Assessment | Symptom Assessment Instrument(s), Number of Symptoms on Instrument; Statistical Analysis Method, Symptom Dimension(s) Used to Create Symptom Clusters | Number of Symptom Clusters, Specific Symptoms Within Each Cluster | Strengths and Limitations |
|---|---|---|---|---|
|
Chen et al., 2006 Title: Symptom Clusters in Cancer Patients Purpose(s): To identify symptom clusters experienced by patients with various cancer diagnoses and validate the conceptual meanings of the identified clusters Design: Cross-sectional |
N=151 Mean age: 50.1 (SD=14.41), range: 18–79 Female: 40.4% Inpatients: n=128 Outpatients: n=23 Diagnosis:
Time of symptom assessment: Range: 0–394 days; median of 24 days since cancer diagnosis
|
Instrument(s): MDASI: 13 items Depression Subscale of the HADS-D: 14 items Analysis: EFA with principal axis factoring Dimension(s): Severity |
3 symptom clusters identified: Sickness symptoms: pain, fatigue, sleep disturbance, lack of appetite, drowsiness GI symptoms: nausea, vomiting Emotional symptoms: distress, sadness |
Strengths: Evaluated conceptual meanings of symptom clusters Limitations: MDASI assessed only 13 symptoms Disease specific symptoms were not evaluated Symptom clusters created using only symptom severity scores Cross-sectional design Primarily evaluated inpatients |
|
Chen et al., 2007 Title: Cancer Symptom Clusters: A Validation Study Purpose(s): To validate the 3 factor symptom structure by using CFA in a larger sample of cancer patients and to examine how 4 disease/treatment variables (diagnosis, disease stage, cancer treatment, hospitalization) and one outcome variable (functional status) were associated with the 3 symptom factors (sickness symptoms, GI symptoms, emotional symptoms) Design: Cross-sectional |
N=321 Mean age: 60.7 (SD=13.78), range: 22–97 Female: 54.5% Outpatients: 76.9% Diagnosis:
|
Instrument(s): MDASI-T: 13 items Analysis: CFA with maximum likelihood estimation. 9 MDASI symptoms used to build the measurement model Dimension(s): Severity |
3 symptom clusters identified: Sickness symptoms: pain, fatigue, disturbed sleep, lack of appetite, drowsiness GI symptoms: nausea, vomiting Emotional symptoms: distress, sadness |
Strengths Evaluated relationships between symptom cluster “scores” and disease and treatment characteristics Demonstrated that higher symptom cluster “scores” were associated with decreased functional status Limitations: Used only 9 symptoms from the MDASI-T Heterogeneous cancer diagnoses Cross-sectional design |
|
Karabulu et al., 2010 Title: Symptom Clusters and Experiences of Patients with Cancer Purpose(s): To characterize the prevalence and severity of symptoms in Turkish patients with cancer and describe the clustering symptoms Design: Cross-sectional |
N=287 Female: 44.3% Diagnosis:
2.9 years after diagnosis |
Instrument(s): MDASI: 13 items Analysis: Hierarchical cluster analysis Dimension(s): Severity Interference |
3 symptom clusters identified: Cluster 1: general activity, mood, work, relations with other people, walking, enjoyment of life. Cluster 2: sleep disturbance, difficulty in remembering, pain, distress, sadness, fatigue, dry mouth, appetite loss Cluster 3: nausea, vomiting, shortness of breath, numbness, drowsiness |
Strengths: First study in Turkish oncology patients Relatively large sample size Limitations: Cross-sectional design Inclusion of interference items in the symptom cluster analysis Symptom clusters were not named MDASI assesses only 13 items |
|
Yamagishi, et al., 2009 Title: Symptom Prevalence and Longitudinal Follow-Up in Cancer Outpatients Receiving Chemotherapy Purpose(s): To clarify the prevalence of physical symptoms and concerns among a representative sample of cancer patients receiving CTX in the outpatient setting; to evaluate symptom clusters in this study population and; to explore longitudinal change and the effects of physical symptoms on the DT Design: Cross-sectional |
N=462 Mean age: 62.0 (SD=11.0), range: 52–74 Female: 55% Diagnosis:
Time of symptom assessment: At start of initial CTX |
Instrument(s): Investigators developed the instrument using 8 physical symptoms from the MDASI; presence or absence of oral problems, fever, and insomnia; overall rating of QOL from EORTC questionnaires; distress thermometer Analysis: Cluster analysis Dimension(s): Authors did not specify what items were included in the cluster analysis |
4 symptom clusters identified: Cluster 1: fatigue, somnolence Cluster 2: pain, dyspnea, numbness Cluster 3: nausea, appetite loss, constipation Cluster 4: psychological distress |
Strengths: Large sample size Single treatment at the induction of CTX Limitations: Cross-sectional study Type of cluster analysis not specified Heterogeneous cancer diagnoses Symptom clusters not named Unclear which symptoms and dimensions were included in the cluster analysis |
|
Yates et al., 2015 Title: Differences in Composition of Symptom Clusters Between Older and Younger Patients Purpose(s): To identify and compare symptom clusters in younger (<60 years) and older (≥60 years) patients undergoing cancer treatment Design: Three combined studies: Symptom Clusters Study: Prospective, longitudinal Fatigue, Pain, and Sleep Study: Longitudinal Symptom Prevalence Study: Descriptive, cross-sectional |
N=263 (<60 years), mean age: 50.3 (SD=7.7) N=330 (≥60 years), mean age: 70.1 (SD=6.5) Group mean age: 61.3 Female: 54.6% Outpatients: 100% Diagnosis (<60, ≥60):
For the longitudinal studies, at the time of recruitment into the study |
Instrument(s): MSAS: 32 items ECOG: functional status rated by clinician (i.e., Australian study) on a 0 to 4 scale KPS: functional status (i.e., U.S. study) on a 0 to 100 scale ECOG: used for combined study on a 0 to 4 scale Analysis: Exploratory factor analysis Dimension(s): Occurrence |
For patients <60 years: 7 symptom clusters were identified: Treatment related: dry mouth, difficulty swallowing, SOB, lack of appetite, nausea, vomiting, lack of energy, change in food tastes, feeling dizzy, cough, weight loss, constipation, pain, feeling drowsy, mouth sores, feeling nervous, I do not look like myself, difficulty concentrating, feeling bloated Mood/Cognitive: worrying, feeling sad, feeling nervous, feeling irritable, difficulty concentrating, lack of energy, difficulty sleeping, problems with sexual interest, I do not look like myself Malaise: lack of energy, feeling drowsy, lack of appetite, nausea, difficulty concentrating, diarrhea, feeling bloated, feeling nervous, difficulty sleeping Treatment related GI: vomiting, nausea, not itching GU: problems with urination, problems with sexual interest Hormonal: sweats, difficulty sleeping, pain, not weight loss CTX toxicity: hair loss, change in food tastes, I do not look like myself, mouth sores, constipation, feeling bloated, swelling of arms/legs, dry mouth For patients ≥60 years: 7 symptom clusters were identified: Malaise: feeling drowsy, lack of energy, difficulty concentrating, difficulty sleeping, feeling nervous, feeling sad, feeling irritable, feeling dizzy, problems with sexual interest, sweats Mood/Cognitive: worrying, feeling sad, feeling nervous, feeling irritable, lack of energy, difficulty concentrating, lack of appetite, nausea, feeling drowsy, change in food tastes, constipation, I do not look like myself, feeling bloated, numbness/tingling in hands/feet Aerodigestive: SOB, cough, dry mouth, difficulty swallowing, lack of appetite, feeling bloated, feeling nervous, lack of energy, nausea, swelling of arms/legs, feeling dizzy, feeling sad, pain, feeling drowsy, difficulty sleeping GU: problems with urination, diarrhea, problems with sexual interest, feeling irritable Nutrition: weight loss, lack of appetite, constipation, change in food tastes, I do not look like myself, lack of energy, feeling drowsy, nausea Aging related: difficulty swallowing, dry mouth, constipation, feeling drowsy, change in food tastes, nausea CTX toxicity: skin changes, hair loss, I do not look like myself, swelling of arms/legs, feeling sad |
Strengths: First study to identify four core symptom clusters and differentiate between symptom clusters based on age groups Found that those ≥60 years had consistently lower symptom occurrence rates Identified that cancer treatment approaches may differ between older and younger patients Large sample size Combined three studies from two geographic regions Limitations: Only used one symptom dimension to create the clusters across the three studies Included patients with metastatic disease which may have had an effect on the symptom experience Excluded patients who had surgery Race/ethnicity not identified |
Abbreviations: CNS, Central Nervous System; CTX, chemotherapy; CFA, Confirmatory Factor Analysis; DT, Distress Thermometer; EORTC, European Organization for Research and Treatment of Cancer; EFA, Exploratory Factor Analysis; GI, gastrointestinal; HADS, Hospital Anxiety and Depression Scale; MDASI, MD Anderson Symptom Inventory; MDASI-T, MD Anderson Symptom Inventory-Taiwanese; MSAS, Memorial Symptom Assessment Scale; QOL, quality of life; RT, radiation therapy; SOB, shortness of breath; UGI, upper-gastrointestinal.