Table 1.

Summary of the main outcomes for all included studies with eHealth interventions.

Study	Main outcome
Jonassaint, 2015 [60]	High correlation between paper and electronic (SMARTa app) pain measurements; high association between pain severity and pain intensity using SMART app; daily entries using SMART app entries: 86% in week 1 and 58% in week 4; higher rates of daily entries with iPads and patients >35 years old; high usability and acceptability as a tool to monitor daily pain and other symptoms.
Hardy, 2016 [57]	Average number of completed sessions was 15.83 (SD 7.73); participants with higher completion rates were female and had lower pain scores; participants who completed scheduled intervention (Cogmed) sessions had improved verbal working memory, as well as visuospatial short-term and working memories.
Leonard, 2017 [61]	Participants tracked their medication usage about 80% at 30- and 90-day follow-up; high disease knowledge retention; adherence to iron chelation improved at 6-month follow-up as measured by serum ferritin levels and medication possession ratio; high satisfaction and acceptability as a tool to monitor medication adherence.
Creary, 2014 [53]	Adherence to hydroxyurea improved at 6-month follow-up as measured by fetal hemoglobin, mean corpuscular volume, and medication possession ratio; high satisfaction with electronic directly observed therapy (e-DOT) as a tool to monitor medication adherence; e-DOT needed 5 minutes or less to complete every day.
Estepp, 2014 [54]	Adherence to hydroxyurea improved as measured by laboratory markers (hemoglobin, fetal hemoglobin, mean corpuscular volume, absolute reticulocyte counts bilirubin levels); adherence to hydroxyurea improved as measured by medication possession ratio; no noticeable change in the number of hospitalizations or emergency room visits.
Pernell, 2017 [63]	Response rate to daily messages varied and was overall <50%; medication adherence self-report improved in the intervention group, but not in controls; asthma control test scores improved in the intervention group in adults, but not children.
Inoue, 2016 [58]	Hydroxyurea adherence rates were 85% as measured by either the electronic pill bottle GlowCap or medication possession ratio; laboratory markers of hydroxyurea adherence varied; a few technical challenges were also reported.
McClellan, 2009 [62]	Participants practiced I-CBTb coping skills with different frequencies; self-report practice rates were higher in older and male participants; high satisfaction as a tool for pain, sleep, coping, and daily activities reporting.
Schatz, 2015 [64]	Number of active psychological coping attempts increased with the intervention; reduction in pain scores when participants used I-CBT skills the day before for higher pain; no association between participants’ skill use and functional activity.
Ezenwa, 2016 [55]	Intervention participants had significant reduction in current pain and stress levels; intervention participants had significant reduction in 2-week pain, but not stress intensity; no differences in total opioid use; high satisfaction with the tablet-based guided relaxation intervention to reduce pain.
Bakshi, 2017 [52]	Pain was reported most of the study days (76%); 50th and 90th percentiles of maximum daily pain directly correlated positively with mean maximum daily pain; proportion of pain-free days inversely correlated with mean maximum daily pain; highest pain diary completion rates were in first 30 days, which decreased over time; high satisfaction with momentary pain reporting and communication with medical team.
Jacob, 2013 [59]	Many children and adolescents reported mild to severe pain at home that did not require further evaluation by a health care professional; reported symptoms varied, including tiredness/fatigue, headache, yellowing of the eyes, and respiratory and musculoskeletal symptoms; higher pain scores were associated with shorter sleep duration and lower sleep quality; having previous history of SCDc-related events, symptoms, and negative thoughts was associated with reporting more frequent and higher-intensity pain; no differences in health care utilization (eg, emergency room visits or hospitalizations); high usability and acceptability as a tool to monitor daily pain and other symptoms.
Gallo, 2014 [56]	Intervention participants reported increased disease and reproductive knowledge scores; high acceptability of the CHOICES intervention; participants provided constructive feedback (eg, content, visualization, animation).
Wilkie, 2013 [65]	Intervention participants reported increased disease and reproductive knowledge scores; intervention participants were more likely to report a parenting plan to avoid SCD or SCD and sickle cell trait; there was an intervention effect on participants’ parenting intention and planned behavior.
Hazzard, 2002 [67]	Participants’ knowledge about SCD and asthma increased; participants reported more positive perceptions of peer support and less negative coping.
Yoon, 2007 [66]	Participants’ SCD knowledge and confidence levels increased significantly.

^aSMART: Sickle cell disease Mobile Application to Record symptoms via Technology.

^bI-CBT: internet-delivered cognitive behavioral therapy.

^cSCD: sickle cell disease.