Patients’ experiences of adjusting insulin doses when implementing flexible intensive insulin therapy: A longitudinal, qualitative investigation

Abstract

Aim

To explore patients’ experiences of using flexible intensive insulin therapy, a regimen requiring them to determine and adjust quick-acting and background/basal insulin doses and mealtime ratios.

Methods

Repeat, in-depth interviews with 30 type 1 diabetes patients converted to flexible intensive insulin therapy recruited from Dose Adjustment for Normal Eating (DAFNE) courses in the UK.

Results

While patients found determination of quick acting insulin doses relatively straightforward, many struggled, over time, to determine the correct mealtime ratios and adjust basal insulin doses independently. Reasons included: lack of confidence and poor analytical skills; deferential attitudes to health professionals; worries about hypoglycaemia; and, lack of record/diary keeping resulting in fixation on current readings and failure to spot patterns and problems. When health professional support was not sought and/or record keeping neglected, patients gradually developed over-reliance on corrective doses to attain blood glucose readings within target ranges.

Conclusion

While patients are motivated to use flexible intensive insulin therapy, they expressed a need for on-going health professional input, particularly to support adjustment of background insulin doses and mealtime ratios. The need to sustain diary/record keeping should be emphasised to patients and provision of a dedicated glycaemic support service is recommended.

Introduction

People with type 1 diabetes are required to use insulin to compensate for the lack of beta cell function. Flexible intensive insulin therapy, comprising long-acting basal insulin (BI) injected once or twice daily, and quick acting (QA) bolus insulin adjusted to carbohydrate intake at meals, is generally recommended for type 1 diabetes management. Similar principles are utilised in pump therapy. By adopting physiological principles, flexible intensive insulin therapy can promote effective diabetes management without increasing, and often reducing, risk of significant hypoglycaemia [1], [2], [3]. This regimen also permits greater dietary flexibility than is possible with other (e.g. twice daily pre-mixed insulin) treatment approaches [2], [4]. Flexible intensive insulin therapy was pioneered in the Diabetes Treatment and Teaching programme in Düsseldorf [5]. It is now used in many countries and is often taught as part of structured education programmes based on the Düsseldorf model [4], [6], an exemplar being the Dose Adjustment for Normal Eating (DAFNE) programme in the UK [4], [7].

Like other programmes, DAFNE draws on theories of empowerment and uses goal-setting and problem-based learning to promote self-efficacy and self-care [6], [8]. Patients are taught how to count carbohydrates (expressed as 10-g carbohydrate portions) and calculate QA mealtime insulin dose requirements as ratios to the number of carbohydrate portions consumed [9]. Patients are advised to undertake regular review of self monitoring of blood glucose readings (normally taken pre-meal and pre-bed) and instructed how to interpret patterns and/or changes in readings to calculate and adjust mealtime ratios and basal insulin dose requirements to meet or maintain pre-prandial and bedtime targets. Patients also learn how to use corrective insulin or additional carbohydrate portions to help maintain blood glucose readings within recommended target ranges (5.5–7.5 mmol/l before breakfast, 4.5–7.5 mmol/l before other meals, 6.5–8.0 mmol/l before bed in the DAFNE programme) [10], [11]. Patients attend the programme over five consecutive days and are taught in groups of 6–8. Courses are normally facilitated by a diabetes specialist nurse and dietitian. Patients are given the opportunity to attend a group follow-up session 6 weeks post-course, with some DAFNE centres also offering group follow-ups at 6 and/or 12 months.

Research undertaken with graduates of DAFNE and similar programmes has highlighted similar, short-term improvements in glycaemic control and quality of life [1], [7], [11], [12], [13] and reductions in incidence of severe hypoglycaemia [3]. However, while improvements in psychological measures may be sustained, patients experience a decline in their glycaemic control over time [3], [14], [15], [16], possibly beginning as early as 1–3 months post-course [8]. The reasons for this glycaemic drift are poorly understood, and have prompted calls for research drawing on patients’ own understandings and experiences [4]. Hence, to understand the clinical outcomes of programmes such as DAFNE, we conducted an in-depth, longitudinal study involving DAFNE course graduates. A key aim was to explore patients’ experiences of, and views about, making adjustments to their insulin doses following their courses and over time. Our objective was to inform development of future resources and professional support for patients, to optimise and sustain effective use of flexible intensive insulin therapy.