The British Diabetic Association (BDA) has received a flood of letters and phone calls about people's concerns in the relation to the effects of genetically engineered (human) insulin. It has been in the midst of the controversy surrounding this insulin and taken a leading part in securing continued supplies of animal derived insulin. The loss of Warnings (LOW) Task Force was set up to address the issues and problems in this area. After receiving two feasibility study reports, the LOW Task Force committee decided to subject those letters received by the BDA on this subject since 1989 which has been kept in a separate file from others dealt with by the Diabetic Care Dept., to a detailed examination. The results of this examination are the subject of this report.

The aim of the examination was to analyse the content of the letters, treating them as an authentic, relevant source of data on the effects of the change-over to 'human' insulin from the patients or their relative's point of view. The range of symptoms complained of, and their related consequences were to be systematically mapped. This data was basically descriptive qualitative material. However, in many cases the content of the histories amounted to clinical evidence which indeed could have been, and possibly was, presented in the diabetic clinic. On occasion, the person's account of symptoms was accompanied by detailed blood sugar and medication evidence.

Where this material has been treated quantitatively in order to map out proportions, careful interpretation is important. This is not epidemiological evidence based on measurement of parameters in a sample of the general diabetic population. This is a sample of nearly 400 persons with problems and the motivation to write about them. Considerable confidence can be attached to the overall pattern of experiences recounted and the relative proportions of symptoms, and to the assumption that they do in fact reflect the nature of the problem where it exists in the wider diabetic population. Only what was mentioned by correspondents could be counted, so that the figures and percentages represent the number of times something was mentioned in the letters. It seems very likely that the numbers are in some cases underestimates of the actual occurrences, but attention is in any case, most usefully focussed on the pattern of experiences rather than actual numbers.

The Sample

All the letters in the file were examined. The letters included in the analysis were those relating to experiences of 384 people of the change-over from animal derived to genetically engineered insulin, and where the original or a photocopy was available. (In a small number of cases only the reply was filed). Not included in the analysis were letters from doctors and other healthcare professionals or from the BDA branch officers asking information or making comments and letters from people worried by what they have heard or read about 'human' insulin and asking for information or advice.

The main analysis and the percentages in the figures are derived from cases where it was clear that the person with diabetes had changed over from using animal derived to genetically engineered insulin either because the correspondent mentioned it, or because it could be deduced from the length of time the person with insulin dependant diabetes (IDD) had had the condition that s/he had previously been using animal derived insulin. In some cases the evidence of a particular case was derived from more than one letter. Sometimes (31%) it was not the person with the diabetes him or herself who wrote to the BDA, but a spouse, relative or friend.

Twenty-eight letters in the file which related to the experiences of the people who were currently using 'human' insulin where it was not clear if they had previously used animal derived insulin and to those who had only ever used 'human insulin, were analysed separately and are included in an appendix (Appendix 1).

In just over half (51%) of the letters the correspondents mentioned the length of time since the person with diabetes had been diagnosed, and this was recorded. Over 90% of these cases had had diabetes for more than 10 years, 73% for over 20 years (Fig.1.) Looking at the whole sample, nearly half had definitely had diabetes for more than 10 years, but in 49% of the cases there was no information about this. This finding provides further substantial evidence that the problem in relation to the change-over to 'human' insulin has been largely among long- standing IDDs.

Experiences of the change to 'human' insulin will be presented in two sections. Section A will report the symptoms and other effects on life of a person with diabetes or their companions under four headings: "Problem with Hypoglycaemia "Deterioration in Diabetic Control "Deterioration in General Health "Effects on the Quality of Life (Fig.3.)These dimensions of the problem obviously overlap, but for analytical purposes it is useful to look at them in detail separately. Section B will examine experiences of treatment by doctors of correspondents' difficulties, and the influence of the media.