Healthcare settings

Four RCTs were performed in a community‐based care setting (Cisneros 2010; Corbett 2003; Rettig 1986; Rönnemaa 1997): patients were recruited from a home care organisation register (Corbett 2003), hospital records (Rettig 1986), the national drug imbursement register (Rönnemaa 1997) or the National Health System database (Cisneros 2010). The care settings of three studies were classified as primary care (Bloomgarden 1987; Frank 2003; Mazzuca 1986): one was performed in a diabetes outpatient clinic in the USA (Bloomgarden 1987), one in a country hospital's outpatient clinic in the USA (Frank 2003) and one in an academic general medicine outpatient clinic in the USA. Four studies were performed in a secondary care setting: one in an outpatient clinic in Australia (Barth 1991), two in secondary outpatient care in the USA (Kruger 1992; Malone 1989) and one in secondary outpatient care in the UK (Lincoln 2008). Finally, one study setting could not be categorised with any of the above, because it was performed in the emergency departments of two community hospitals in the USA (Borges 2004).

Participants' risk of foot ulceration

In four of the 12 included RCTs, patients were at high risk of foot ulceration (Cisneros 2010; Corbett 2003; Lincoln 2008; Malone 1989). In Malone 1989 all patients were referred to podiatry or vascular surgery prior to study entry and had foot infection, ulceration or prior amputation. In Lincoln 2008 all participants had newly healed diabetic foot ulcers. In Corbett 2003 patients were excluded if they had a history of foot amputation, but it follows from the presence of important risk factors at baseline that the studied population was at high risk for foot ulceration: loss of protective sensation was present in 70%, impaired lower extremity circulation in 67% and foot deformity in 50%. Finally, in Cisneros 2010 all patients had diabetic neuropathy and most had additional risk factors such as plantar overpressure, deformity and previous foot ulceration. In four RCTs patients were at low or medium risk of foot ulceration (Barth 1991; Bloomgarden 1987; Frank 2003; Rönnemaa 1997). In Rönnemaa 1997 patients were even excluded if they had any need for podiatry. Finally in four RCTs, the level of risk for ulceration or amputation could not be determined (Borges 2004; Kruger 1992; Mazzuca 1986; Rettig 1986).

Interventions

Three RCTs compared the effectiveness of a patient education programme on diabetes in general (which included a component of foot care education) compared with usual care (Bloomgarden 1987; Mazzuca 1986; Rettig 1986). In one of these studies, the content of the educational programme was preset and consisted of nine group patient education sessions, one of which was about foot care and skin hygiene (Bloomgarden 1987). In the other two studies, the content of the educational programme was tailored to patients' individual needs (Mazzuca 1986; Rettig 1986). In Mazzuca 1986 those educational needs were identified using a set of safety‐level objectives selected by a multidisciplinary group of healthcare professionals. These objectives covered seven areas of patient education, of which foot care was one. In the other study areas of diabetes self‐management, patients most in need of improvement were determined using an assessment instrument (100 short answer and yes‐no questions, brief patient demonstrations of urine testing and insulin injection techniques) (Rettig 1986). In both studies, participants received a variable number of educational sessions.

In addition to Mazzuca 1986 and Rettig 1986, there were two more RCTs that adopted the concept of education tailored to patients' individual needs, but in these studies the educational interventions were only directed at improving foot care (Borges 2004; Corbett 2003) and they were less intensive than in Mazzuca 1986 and Rettig 1986. In Corbett 2003 a single 10‐ to 20‐minute educational session, combined with written instructions, was compared with no intervention, and in Borges 2004 a 15‐minute educational session after a risk assessment for foot ulceration was compared with risk assessment alone and with no intervention at all.

In the remaining six RCTs, an intensive foot care education programme was compared with a less proactive intervention (Barth 1991; Cisneros 2010; Frank 2003; Kruger 1992; Lincoln 2008; Malone 1989; Rönnemaa 1997). This, however, does not mean that the interventions in these studies were all similar. In two studies the intervention was only one hour of patient education, reinforced by hand‐outs (Lincoln 2008; Malone 1989). In Malone 1989, this was compared with routine patient education, and in Lincoln 2008 with written instructions only. In Rönnemaa 1997, patients in the intervention group also received 45 minutes of foot care education, but this was combined with a variable number of follow‐up visits at a podiatry clinic. The control intervention consisted of written instructions on foot care only. In the other studies, the educational interventions were more comprehensive, more intensive or both. In Frank 2003, for example, the intervention comprised viewing a videotape about proper foot care, a 30‐ to 40‐minute individualised educational session, a foot ulceration risk assessment, hand‐outs, a foot care checklist, a bag of foot care supplies and weekly reminder telephone calls. Control group patients received a foot ulceration risk assessment only. In Cisneros 2010 people in the intervention group received four 90‐minute therapeutic education sessions on the complications of diabetes, disease treatment, inspection and foot hygiene and choice and use of proper footwear. In addition, participants received footwear after completion of the educational programme. This was compared with routine care. In two other studies a basic educational programme on diabetes in general was provided to all study participants and supplemented by specific foot care education in the intervention group (Barth 1991; Kruger 1992). In Barth 1991, the general diabetes education consisted of 14 hours of group education and included a one‐hour lecture on foot care. In addition to that, the intervention group followed nine hours of group education about the diabetic foot (Barth 1991). In Kruger 1992, the general diabetes education consisted of a one‐week course, which included viewing an instructional videotape on foot care. In the intervention group this was supplemented with a 'hands‐on' foot care approach, a patient education kit and daily foot care sheets (Kruger 1992).

Duration of follow‐up

The median time to follow‐up was six months (Barth 1991; Kruger 1992; Rettig 1986), ranging from only four weeks (Borges 2004; Frank 2003) to seven years (Rönnemaa 1997).

Primary outcomes

The incidence of foot ulceration or amputation was only reported in Bloomgarden 1987: 146 patients had no foot lesion at the initial evaluation and since only two severe foot lesions (ulceration or amputation) were observed in both the intervention and the control group during follow‐up of approximately 1.5 years, the effect was not significant. Also in the subgroup of patients with callus, nail dystrophy or fungal infection at baseline (n = 100) and in the subgroup of patients with a previous ulcer or amputation at baseline (n = 20), no significant effects of the intervention were observed.

Secondary outcomes

After six months' follow‐up, Rettig 1986 reported that foot care knowledge scores were significantly higher in the intervention group (mean score: 62 ± 1.7 SE) compared with the control group (mean score: 53 ± 1.8 SE) (P = 0.001), but this had not resulted in positive effects on foot appearance and foot care skills score. Mazzuca 1986 reported no significant improvements in foot care knowledge, and Bloomgarden 1987 found no significant improvements in behaviour assessment scores, neither in the occurrence of callus, fungal infection and nail dystrophy.

It should be noted that in both Mazzuca 1986 and Bloomgarden 1987, adherence to the intervention and follow‐up were poor. In Mazzuca 1986, only 52% of patients were followed up, and only 67% of patients requiring foot care completed treatment. Bloomgarden 1987 reported that 77% of patients who gave consent completed follow‐up, but only 50% of patients in the intervention group adhered to the intervention. Rettig 1986 did not report adherence to the intervention.

Primary outcomes

Not reported in any of the included RCTs.

Secondary outcomes

After a 10‐ to 20‐minute individualised foot care education session at home, Corbett 2003 found that participants in the intervention group (n = 19) had significantly greater foot care knowledge (P = 0.03) and improved self‐care practices (P = 0.007) compared with participants in the control group (n = 16). This study, however, was limited by a small sample size and short duration of follow‐up (six weeks). In Borges 2004, self‐reported behaviour assessment scores were significantly improved after one month of follow‐up in both the intervention group, who received a 15‐minute education session (P < 0.01), and in the control group, who received no intervention at all (P < 0.05). Four of 16 foot self‐care behaviours were significantly more frequently observed in the intervention group compared with the control group. Paradoxically, foot care knowledge increased only in the control group but not in the intervention group.

Primary outcomes

In Malone 1989, 34 foot ulcers, 28 lower‐extremity amputations and 4 foot infections were observed during one year of follow‐up of 182 patients. A marked reduction in ulcer incidence (intervention 8, control 26) and amputation rate (intervention 7, control 21) was observed in the intervention group. It should be noted, however, that outcomes were reported per limb (n = 354) instead of per person (n = 182). Therefore, a single person could have had two events, although multiple events on the same limb were reported as one. This may have resulted in overestimation of the effect sizes (RR foot ulceration 0.31, 95% CI 0.14 to 0.66; 354 limbs, one trial, Analysis 1.1, and RR amputation 0.33, 95% CI 0.15 to 0.76, 354 limbs, one trial, Analysis 1.2).

These findings were not reproduced in the study by Lincoln 2008, in which 71 foot ulcers and 18 lower‐extremity amputations were observed during one‐year follow‐up of 172 participants. No effects of the intervention on primary outcomes were observed. The RR for foot ulceration was 1.00 (172 participants, one trial, Analysis 1.3) and the RR for lower extremity amputation was 0.98 (172 participants, one trial, Analysis 1.4).

In Cisneros 2010, 22 foot ulcers were observed in 51 people. The accompanying survival curve in the trial report showed a trend towards longer event‐free survival in intervention‐group participants, but this was not statistically significant (P = 0.362; hazard ratio (HR) not reported). In Rönnemaa 1997 ulcerations and amputations were reported, but these occurred too infrequently to be evaluated conclusively.

Secondary outcomes

In Lincoln 2008 a statistically significant increase in the persons behaviour assessment scores was reported in the intervention group (P = 0.03), but for this outcome only 72% of people were followed up. Moreover, the authors questioned the reliability of their assessment tool.

Rönnemaa 1997 found a significant increase in foot care knowledge in the intervention group after one year of follow‐up (P = 0.004). Also the persons behaviour assessment scores (5.4 increased to 7.0), the mean diameter of callosities (calcaneal region 40.5 mm decreased to 25.5 mm, P = 0.065; other regions 16.6 mm decreased to 11.4 mm, P < 0.001) and the presence of callus in other regions than the calcaneal region (54.4% decreased to 39.5%, P < 0.009) initially improved after the intervention. However, after seven years of follow‐up, the control group had made up all these arrears.

In Frank 2003, foot care knowledge was marginally but significantly better in the intervention than in the control group four weeks after the educational intervention. Adherence to one of the four daily foot care behaviours studied (wearing shoes and socks) was significantly more improved in the intervention group than in the control group, but this did not account for adherence to the other three foot care behaviours studied (checking feet, washing and drying feet, applying lotion).

In Barth 1991, already after one month of follow‐up a significant reduction of foot problems requiring treatment (P < 0.001) and an increase in foot care routine compliance (P < 0.001) was seen in the intervention group. Also foot care knowledge improved in both groups, but most in the intervention group (P < 0.001). Improvements were maintained until after six months of follow‐up, but the differences between intervention and control group diminished. Kruger 1992 also found almost similar improvements of foot care knowledge scores in both the intervention and control group (intervention 9.1 increased to 10.0, control 8.7 increased to 9.9) and no significant differences in the status of the participants' feet after six months of follow‐up. Some (daily foot washing, trimming of toenails), but not all foot care behaviours (daily foot inspection, use of pumice stones, keeping toenails shorter) improved in the intervention group. However, this study dealt with small groups (23 people in the intervention group and 27 in the control group), and also had a relatively high dropout rate (40%).