P E Hasvold and R Wootton Telephone and SMS reminders Table 1 Papers selected for review Geraghty, 2007 Automatic Study Adams, 2004 Booth, 2004 Bos, 2005 Chen, 2008 Corﬁeld, 2008 da Costa, 2010 Dockery, 2001 Downer, 2005 Downer, 2006 Foley, 2009 Hardy, 2001 Hashim, 2001 Haynes, 2006 Irigoyen, 2000 Koshy, 2008 Kruse, 2009 Lee, 2003 Leong, 2006 MacDonald, 2000 Maxwell, 2001 McPhail 2010 Milne, 2006 Parikh, 2010 Perron, 2010 Reti, 2003 Roberts, 2007 Satiani, 2009 Sawyer, 2002 Reminder type (manual or automatic) Manual Manual Manual Automatic Manual Automatic Manual Automatic Manual Automatic Automatic Automatic Manual Manual Manual Manual Automatic Automatic Manual Manual Automatic Manual Automatic Automatic Automatic Manual Automatic Manual Manual Manual Automatic Manual Study size 2823 100 216 1848 1077 29014 162 2864 45110 709 8966 325 823 515 653 9959 1027 161 993 719 1370 145 16400 9835 2123 74 504 8766 171 Country Study design Australia Telephone reminders for 3 months; retrospective comparison with 12.2 previous year UK Telephone reminders for 4 months; concurrent and matched 40.0 groups Netherlands Telephone and SMS reminders for 0.75 months; concurrent 6.5 groups China Telephone and SMS reminders for 2 months; RCT 19.6 UK Telephone reminders for 2 months; retrospective control group 21.4 Brazil SMS reminders for 11 months; concurrent, non-randomized 25.6 ( patients who accepted SMS were sorted into the intervention group) UK Telephone reminders for 2 months; before and after study 29.5 Australia SMS reminders for 1 month; retrospective comparison with 23.4 previous month Australia SMS reminders for 3 months; retrospective comparison with 19.5 previous year UK SMS reminders for 1 month; retrospective comparison with 23.9 previous year Ireland SMS reminders for 36 months; historical control group consisted of 33.6 patients not sent SMS in the intervention period UK Telephone reminders; duration not stated; single centre, 7.3 prospective, non-randomized, controlled study USA Telephone reminders for 1 month; RCT 25.6 USA Telephone reminders for 7 months; non-randomized controlled 11.6 study USA Telephone reminders for 5 months; non-randomized controlled 35.0 trial UK SMS reminders for 6 months; non-randomized controlled trial 18.1 Denmark SMS reminders for 1 month; prospective cohort study 10.0 Ireland Telephone reminders for 2 months; before and after study 23.3 Malaysia Telephone and SMS reminders for 7 months; RCT 51.9 New Zealand Telephone reminders for 36 months; non-randomized controlled 24.4 study USA SMS reminders for 2 months; RCT 40.0 USA SMS reminders for 12 months; non-randomised controlled study? 72.5 UK SMS reminders for 2 months; retrospective study 15.4 USA Telephone and SMS reminders for 5 months; RCT 23.1 Switzerland Telephone reminders for 3 months; RCT 11.4 New Zealand Telephone reminders for 3 months; RCT 27.0 UK Telephone reminders for 10 months; RCT 20.9 USA SMS reminders for 17 months; non-randomized controlled study 5.9 Australia Telephone reminders for 6 months; RCT 20.0 reminders (i.e. automated phone messages or SMS messages). The study characteristics are summarised in Table 2. The median DNA rate reported at baseline (i.e. in the control group) was 23%. All studies except one reported that the intervention improved the DNA rate. The median DNA rate reported after the intervention was 13%, see Table 3. Nine of the 29 studies were randomised controlled trials. The median study quality score was seven, see Figure 2. There was little evidence for publication bias based on a funnel plot, see Figure 3. There was no obvious relation between effect size and the time at which the reminder was issued, see Figure 4 (Spearman correlation 0.18). Three of the 29 studies stated that the reminder was sent within a week of the appointment, which we assumed to be within 3.5 days for the purposes of analysis. The effect of reminders on DNA rates was higher for manual reminder calls than for 360 automated calls; this was true for both the absolute and the relative change in DNA rates, see Figure 5 and 6 respectively. The mean estimates of effect size are summarised in Table 4. Costs and savings None of the papers included costs and savings data to the standard of accepted guidelines for economic evaluation in health care. An estimate of the cost of the intervention was reported in 16 of the papers. Two of the estimates were not included in the present study as the cost estimates depended on circumstances or cost sharing models that were particular to the case. The cost estimates were converted into Euros, using the exchange rate giving the highest costs for the year the paper was published. The average estimated costs in these 14 studies was E 0.41 per patient. The mean cost of phone reminders was E 0.90, Journal of Telemedicine and Telecare Volume 17 Number 7 2011 Baseline Intervention DNA % DNA% M: 2.7 A: 2.0 M: 11.7 A: 12.5 19.7 19.4 9.0 14.0 17.9 14.2 9.8 10.4 22.0 1.4 19.8 4.7 34.9 11.2 5.9 5.7 M: 40.4 A: 41.0 18.4 36.9 20.4 12.0 M: 13.6 A: 17.3 7.8 8.1 13.8 8.9 7.9