Procedures
Patients directly contacted the project coordinator or were introduced by their health care provider. The project coordinator explained the study in more detail, and if the patient agreed to participate, the project coordinator obtained thier informed consent. Participants completed the study materials in a private space in the clinic immediately after or were scheduled for a separate visit at a convenient time and location. Participants with known or observed difficulties with reading completed the questionnaires as an interview. We allowed participants who were unable to complete the forms in one visit to take them home or schedule a follow-up visit to complete them. We asked participants who took the questionnaires home to return them within 2 business days and provided them with a stamped addressed envelope. Participants were compensated with gift cards for their involvement.
Measures
Demographics and Clinical Characteristics
Participants completed an Individual Utilization Questionnaire created for the SCDTDP grantees [32], either as an interview or in paper and pencil format. Participants indicated their age, race and ethnicity, education level, type of insurance, and annual household income. They indicated the type of SCD, number of hospital days and emergency department (ED) visits in the previous 12 months, disease-modifying therapies including hydroxyurea or transfusions, and lifetime incidence of sickle cell–related complications. Complications included pain, acute chest syndrome, fever, severe infection, stroke, kidney damage, gallbladder attack, spleen problems and priapism. Medical data was verified by reviewing medical records when possible; the clinical databases in the hematology/oncology department at the sponsoring hospital are maintained using Microsoft SQL Server, a relational database management system designed for the enterprise environment. However, not all of the participating institutions were linked via this common clinical database or by an electronic health record at the time the study was conducted.
Barriers to Care
We modified a checklist of barriers to accessing health care for patients with a range of chronic conditions [33] to create a SCD-specific checklist [34]. The final checklist consists of 53 items organized into 8 categories including insurance, transportation, accommodations and accessibility, provider knowledge and attitudes, social support, individual barriers such as forgetting or difficulties understanding instructions, emotional barriers such as fear or anger, and barriers posed by SCD itself (eg, pain, fatigue). Participants check off any applicable barrier, yielding a total score ranging from 0 to 53. The checklist overall has demonstrated face validity and test-retest reliability (Pearson r = 0.74, P < 0.05).
Depressive Symptoms
Adults with SCD completed the PHQ-9, the 9-item depression scale of the Patient Health Questionnaire [35]. The PHQ-9 is a tool for assisting primary care clinicians in assessing symptoms of depression, based on criteria from the Diagnostic and Statistical Manual 4th edition (DSM-IV [36]). The PHQ-9 asks about such symptoms as sleep disturbance and difficulty concentrating over the past 2 weeks with scores ranging from 0 (Not at all) to 3 (Every day). The total symptom count is based on the number of items in which the respondent answered as “more than half of days” or greater, and scores are categorized as reflecting no (< 10), mild (10–14), moderate (15–19) or severe (≥ 20) symptoms of depression. Respondents indicate how difficult the symptoms make it for them to engage in daily activities from 0 (Not difficult at all) to 3 (Extremely difficult). The sensitivity and diagnostic and criterion validity of the PHQ-9 have been established [37]. The internal consistency of the PHQ-9 is high, with α > 0.85 in several studies and 48-hour test-retest reliability of 0.84. The PHQ has been used widely, including with African-American and Hispanic populations, and with individuals with chronic conditions [38].