Psychological risk factors of micro- and macrovascular outcomes in primary care patients with type 2 diabetes: rationale and design of the DiaDDZoB Study

Background

Depression is a common psychiatric complication of diabetes, but little is known about the natural course and the consequences of depressive symptoms in primary care patients with type 2 diabetes. While depression has been related to poor glycemic control and increased risk for macrovascular disease, its association with microvascular complications remains understudied. The predictive role of other psychological risk factors such as Type D (distressed) personality and the mechanisms that possibly link depression and Type D personality with poor vascular outcomes are also still unclear.

Methods/Design

This prospective cohort study will examine: (1) the course of depressive symptoms in primary care patients with type 2 diabetes; (2) whether depressive symptoms and Type D personality are associated with the development of microvascular and/or macrovascular complications and with the risk of all-cause or vascular mortality; and (3) the behavioral and physiological mechanisms that may mediate these associations. The DiaDDZoB Study is embedded within the larger DIAZOB Primary Care Diabetes study, which covers a comprehensive cohort of type 2 diabetes patients treated by over 200 primary care physicians in South-East Brabant, The Netherlands. These patients will be followed during their lifetime and are assessed annually for demographic, clinical, lifestyle and psychosocial factors. Measurements include an interviewer-administered and self-report questionnaire, regular care laboratory tests and physical examinations, and pharmacy medication records. The DiaDDZoB Study uses data that have been collected during the original baseline assessment in 2005 (M₀; N = 2,460) and the 2007 (M₁; N = 2,225) and 2008 (M₂; N = 2,032) follow-up assessments.

Discussion

The DiaDDZoB Study is expected to contribute to the current understanding of the course of depression in primary care patients with type 2 diabetes and will also test whether depressed patients or those with Type D personality are at increased risk for (further) development of micro- and cardiovascular disease. More knowledge about the mechanisms behind this association is needed to guide new intervention studies.

Plasma and erythrocyte fatty acid patterns in patients with recurrent depression: a matched case-control study

Background

The polyunsaturated fatty acid (PUFA) composition of (nerve) cell membranes may be involved in the pathophysiology of depression. Studies so far, focussed mainly on omega-3 and omega-6 PUFAs. In the present study, saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and PUFAs of the omega-3, -6 and -9 series in plasma and erythrocytes of patients with recurrent major depressive disorder (MDD-R) were compared with controls.

Methodology and Principal Findings

We carried out a case-control study. The sample consisted of 137 patients with MDD-R and 65 matched non-depressed controls. In plasma and erythrocytes of patients with MDD-R the concentrations of most of the SFAs and MUFAs, and additionally erythrocyte PUFAs, all with a chain length >20 carbon (C) atoms, were significantly lower than in the controls. In contrast, the concentrations of most of the shorter chain members (≤18C) of the SFAs and MUFAs were significantly higher in the patients. Estimated activities of several elongases in plasma of patients were significantly altered, whereas delta-9 desaturase activity for C14∶0 and C18∶0 was significantly higher.

Conclusions/Significance

The fatty acid status of patients with MDD-R not only differs with regard to omega-3 and omega-6 PUFAs, but also concerns other fatty acids. These alterations may be due to: differences in diet, changes in synthesizing enzyme activities, higher levels of chronic (oxidative) stress but may also result from adaptive strategies by providing protection against enhanced oxidative stress and production of free radicals.

Prevalence of comorbid depression is high in out-patients with Type 1 or Type 2 diabetes mellitus. Results from three out-patient clinics in the Netherlands

AIMS

Depression is common in diabetes, but the scope of the problem and associated correlates are not well established in specialist diabetes care. We aimed to determine the prevalence of depression among adult outpatients with Type 1 (T1DM) or Type 2 diabetes (T2DM) using both self-report measures and a diagnostic interview, and to establish demographic and clinical characteristics associated with depressive affect.

METHODS

A random sample of 2055 diabetes out-patients from three diabetes clinics was invited to participate. Depressive affect was assessed using the World Health Organization-5 Well Being Index (WHO-5), the Centre for Epidemiologic Studies-Depression scale (CESD) using predefined cut-off scores, and depressive disorder with the Composite International Diagnostic Interview (CIDI). Associations between depression and patient characteristics were explored using regression analyses.

RESULTS

Seven hundred and seventy-two patients completed the depression questionnaires. About one-third of T1DM patients and 37-43% of T2DM patients reported depressive affect (WHO-5). The prevalence of depressive affect (CESD) was 25% and 30% for men and women with T1DM, and 35% and 38% for men and women with T2DM, respectively. Based on the CIDI, 8% of T1DM patients (no gender difference) and 2% of men and 21% of women with T2DM suffered from a depressive disorder. Depressive affect was associated with poor glycaemic control and proliferative retinopathy in T1DM, while non-Dutch descent, obesity and neuropathy were correlates in T2DM.

CONCLUSIONS

Depressive symptoms and major depressive disorder constitute a common comorbid problem among Dutch out-patients with T1DM or T2DM and appear particularly common in migrants and women with T2DM.

Should we screen for emotional distress in type 2 diabetes mellitus?

Emotional problems such as depression, anxiety and diabetes-specific distress are common in patients with type 2 diabetes mellitus (T2DM) but often remain unrecognized and thus untreated. The present Review focuses on the extent of this problem and discusses whether we should screen for depression, anxiety and diabetes-specific distress in patients with this condition. Depression has received by far the greatest attention from researchers. Strong evidence exists that depression affects 10-20% of patients with T2DM, but it is often unrecognized. Several guidelines have therefore recommended periodic assessments of emotional well-being in patients with T2DM. However, this recommendation is not based on strong evidence, as the effects of screening (case-finding) on psychological outcomes and diabetes outcomes have not been tested in a randomized controlled study. Results from studies in patients without T2DM have shown that screening for depression does not improve outcomes. On the other hand, collaborative care approaches for depression in patients with type 1 diabetes mellitus (T1DM) or T2DM seem to be effective. Intervention studies for anxiety or diabetes-specific emotional distress are currently lacking, and further research that can help to optimize antidepressant treatment is also urgently needed.

Associations between vascular co-morbidities and depression in insulin-naive diabetes patients: the DIAZOB Primary Care Diabetes study

AIMS/HYPOTHESIS

The aim of the study was to determine the prevalence of depression in insulin-naive diabetes patients and to investigate the associations between different forms of vascular co-morbidity and depression.

METHODS

Cross-sectional data were used from a primary-care sample of 1,269 insulin-naive (i.e. not using insulin therapy) diabetes patients participating in the DIAZOB Primary Care Diabetes study. Demographics, vascular co-morbidities, clinical and lifestyle characteristics, and psychosocial factors were assessed. Depression symptoms were measured with the Edinburgh Depression Scale, with a score >11 defined as depression. The chi (2) and Student's t tests were used to compare groups with and without vascular co-morbidities. Rates and odds ratios of depression were calculated for each vascular co-morbidity, with diabetes only as the reference group, correcting for age and sex. Single and multiple logistic regression analyses were performed to test a more comprehensive model regarding the likelihood of depression in diabetes.

RESULTS

The prevalence of depression was 11% in the total sample with little difference between the groups with and without any vascular co-morbidity (11.2% vs 10.0%). Single vascular co-morbidities were not associated with increased rates of depression. The final model predicting depression included: having multiple vascular co-morbidities compared with none; having less social support; having experienced a recent stressful life event; female sex; and being a smoker.

CONCLUSIONS/INTERPRETATION

Rates of depression in those with one additional vascular co-morbidity did not differ from patients with diabetes only. Vascular co-morbidities were only associated with higher depression scores in case of multiple co-morbidities.

Insulin therapy and quality of life. A review

Three central goals in the treatment of diabetes mellitus are (1) the avoidance of hyperglycaemia to prevent the development or progression of diabetes complications over time, (2) the avoidance of hypoglycaemia and (3) the maintenance or achievement of good quality of life. Insulin is the most powerful agent that can be used to control blood glucose levels. This article reviews the studies that have investigated the effects of different types of insulin and insulin delivery techniques on quality of life of patients with type 1 or type 2 diabetes. First, the concept of 'quality of life' (QoL) is defined and different ways of measuring QoL are explained. Secondly, the effects of different aspects of insulin therapy on QoL are reviewed: (1) the phenomenon of 'psychological insulin resistance'; (2) the effects of different types of insulin: regular insulin versus short-acting insulin analogues, long-acting insulin analogues or biphasic mixtures; (3) multiple daily injections versus pump therapy. Having multiple complications of diabetes is clearly associated with decreased QoL. Results from large studies such as the Diabetes Control and Complications Trial (DCCT) and United Kingdom Prospective Diabetes Study (UKPDS) suggest that intensive treatment itself does not impair QoL. Recent findings further suggest that pump therapy, compared to multiple daily injections, has beneficial effects on QoL. The fact that multiple tools are used to assess QoL makes it difficult to draw conclusions regarding the effects of different types of insulin on QoL. More work on the standardization of the assessment of QoL in diabetes is urgently needed.

Serious diabetes-specific emotional problems in patients with type 2 diabetes who have different levels of comorbid depression: a Polish study from the European Depression in Diabetes (EDID) Research Consortium

OBJECTIVE

Depression is a common psychiatric problem in patients with type 2 diabetes (DM2). A common view is that the burden of having DM2 contributes to the development of depression in DM2. Aim of the present study was to compare the levels of diabetes-specific emotional problems of DM2 patients with diagnosed depression with those with a subclinical form of depression and those without depression.

METHODS

A cross-sectional study was conducted in 101 DM2 patients (51 men and 50 women, mean age = 63,17; SD = 10,74) who completed a standardized, structured psychiatric diagnostic interview (MINI), the Beck Depression Inventory, the Hamilton Depression Rating Scale as well as the Problem Areas in Diabetes (PAID) scale (a 20-item measure, with an overall scale measuring diabetes-related emotional distress and four subscales [negative emotions, treatment-related problems, food-related problems, lack of social support]).

RESULTS

A depression diagnosis was made in 35% (n = 35) of the participants, 24% (n = 24) had a subclinical form of depression, 42% (n = 42) were not diagnosed with any kind of depressive disorder. Diabetes-specific emotional problems were most common in DM2 patients with a depressive disorder (significantly highest PAID score: 39) compared to patients with subclinical depression or no depression. In the group of non-depressed patients, only 14% agreed to have four or more (somewhat) serious diabetes-specific problems. In those with subclinical depression, this percentage was 42% and in those with a depressive disorder 49% (P < 0.001).

CONCLUSIONS

Diabetes-related emotional problems are particularly common among DM2 patients with comorbid clinical depression and to a lesser extent in patients with subclinical depression, compared to non-depressed DM2 patients. Male diabetes patients with a depressive disorder are particularly vulnerable to develop high levels of diabetes-specific emotional distress. Major differences between the three groups mainly concern the diabetes-specific problems connected with the illness.

Depressive symptoms are associated with physical inactivity in patients with type 2 diabetes. The DIAZOB Primary Care Diabetes study

BACKGROUND

Depression is a common complication of type 2 diabetes, associated with poor disease outcomes such as impaired glycaemic control, cardiovascular disease and increased mortality. The mechanisms behind these associations are unclear. Depression might contribute to poor disease outcomes through decreased physical activity.

OBJECTIVE

To test whether type 2 diabetes patients with elevated depression scores are more often physically inactive.

METHODS

Demographic features, clinical factors, level of physical inactivity and depressive symptoms were assessed in 2646 primary care patients with type 2 diabetes. Sequential multiple logistic regression analyses [odds ratio, 95% confidence interval (CI)] were performed to test the association between depressive symptoms and physical inactivity.

RESULTS

About 48% of the respondents were physically inactive. Elevated depressive symptoms were found in 14% of the respondents. After adjustment for potential confounders, the odds for being physically inactive were almost doubled in depressed patients with type 2 diabetes 1.74 (95% CI 1.32-2.31).

CONCLUSIONS

Presence of depressive symptoms almost doubles the likelihood of physical inactivity in patients with type 2 diabetes. Longitudinal studies are needed to investigate whether physical inactivity forms the link between depression and poor disease outcomes.

Depression and quality of life in patients with diabetes: a systematic review from the European depression in diabetes (EDID) research consortium

Diabetes patients are known to have a worse quality of life than individuals without diabetes. They also have an increased risk for depressive symptoms, which may have an additional negative effect on their quality of life. This systematic review summarizes the current knowledge on the association between depressive symptoms and quality of life in individuals with diabetes. A systematic literature search using MEDLINE, Psychinfo, Social SciSearch, SciSearch and EMBASE was conducted from January 1990 until September 2007. We identified studies that compared quality of life between diabetic individuals with and without depressive symptoms. Twenty studies were identified, including eighteen cross-sectional and two longitudinal studies. Quality of life was measured as generic, diabetes specific and domain specific quality of life. All studies reported a negative association between depressive symptoms and at least one aspect of quality of life in people with diabetes. Diabetic individuals with depressive symptoms also had a severely lower diabetes specific quality of life. Generic and domain specific quality of life were found to be mild to moderately lower in the presence of depressive symptoms. Therefore, increased awareness and monitoring for depression is needed within different diabetes care settings.

Symptoms of depression and diabetes-specific emotional distress are associated with a negative appraisal of insulin therapy in insulin-naïve patients with Type 2 diabetes mellitus. A study from the European Depression in Diabetes [EDID] Research Consortium

AIMS

A meta-analysis concluded that depression is associated with poor glycaemic control in Type 2 diabetes (DM2). In DM2 patients with deteriorating glycaemic control, the initiation of insulin therapy is often postponed. The aim of the present study was to determine whether symptoms of depression and diabetes-specific emotional distress are associated with a more negative appraisal of insulin therapy.

METHODS

We collected cross-sectional data in two outpatient university clinics in Istanbul, Turkey. The study sample consisted of 154 insulin-naïve patients with DM2. A self-report questionnaire was used to obtain demographic and clinical data. Main instruments were the Centre for Epidemiologic Studies Depression Scale, (CES-D), the Problem Areas In Diabetes scale (PAID) and the Insulin Treatment Appraisal Scale (ITAS).

RESULTS

Analysis of variance revealed that patients with a higher depression score rated insulin therapy significantly more negative then patients with lower depression scores. Moreover, 47% of patients with a high depression score had a negative appraisal of insulin therapy on 7 or more of the 20 ITAS-items, compared to 25 to 29% of those with low-moderate depression scores. Multiple regression analyses showed that a negative appraisal of insulin therapy was significantly associated with higher depression and diabetes-distress scores and low education, but not with sex, age or duration of diabetes.

CONCLUSIONS

Our results suggest that in insulin-naïve Type 2 diabetes patients, higher levels of depression and diabetes-distress tend to be associated with more negative beliefs about insulin. Whether these negative attitudes translate into postponing initiation of insulin therapy needs to be tested in longitudinal research.

Symptoms of depression in people with impaired glucose metabolism or Type 2 diabetes mellitus: The Hoorn Study

OBJECTIVE

To study the prevalence and risk factors of depressive symptoms, comparing subjects with normal glucose metabolism (NGM), impaired glucose metabolism (IGM) or Type 2 diabetes mellitus (DM2).

RESEARCH DESIGN AND METHODS

Cross-sectional data from a population-based cohort study conducted among 550 residents (276 men and 274 women) of the Hoorn region, the Netherlands. Levels of depressive symptoms were measured using the Centre for Epidemiologic Studies Depression Scale (CES-D score > or = 16). Glucose metabolism status was determined by means of fasting and post-load glucose levels.

RESULTS

The prevalence of depressive symptoms in men with NGM, IGM and DM2 was 7.7, 7.0 and 15.0% (P = 0.19) and for women 7.7, 23.1 and 19.7% (P < 0.01), respectively. Depression was significantly more common in women with IGM [odds ratio (OR) = 3.60, 95% confidence interval (CI) = 1.57 to 8.28] and women with DM2 (OR = 3.18, 95% CI = 1.31 to 7.74). In men, depression was not associated with IGM (OR = 0.90, 95% CI = 0.32 to 2.57) and non-significantly more common in DM2 (OR = 2.04, 95% CI = 0.75 to 5.49). Adjustment for cardiovascular risk factors, cardiovascular disease and diabetes symptoms reduced the strength of these associations.

CONCLUSIONS

Depressive symptoms are more common in women with IGM, but not men. Adjustment for cardiovascular risk factors, cardiovascular disease and diabetes symptoms partially attenuated these associations, suggesting that these variables could be intermediate factors.

No evidence for increased self-reported cognitive failure in Type 1 and Type 2 diabetes: a cross-sectional study

AIMS

Mild cognitive deficits have been determined in both types of diabetes using neurocognitive tests. Little is known about the degree to which patients complain about their cognitive functioning. This study set out to investigate the magnitude and correlates of self-reported cognitive failure in adult out-patients with Type 1 and Type 2 diabetes.

METHODS

Subjective cognitive functioning was measured in 187 diabetic patients using the Cognitive Failures Questionnaire (CFQ). Demographic and clinical characteristics were retrieved from the medical records. The Patient Health Questionnaire 9 items (PHQ-9) was self-administered along with the CFQ to correct for the confounding effect of depression.

RESULTS

Analyses were based on 55 patients with Type 1 diabetes and 100 patients with Type 2 diabetes. No difference in mean CFQ score was observed between Type 1 and Type 2 diabetic patients or between Type 1 diabetic patients and healthy control subjects. Female patients with Type 2 diabetes reported significantly fewer cognitive complaints compared with female healthy control subjects. None of the demographic variables and diabetes-related complications was associated with subjective cognitive complaints. A strong positive association was found between depression symptomatology and frequency of self-reported cognitive failure.

CONCLUSIONS

Our study could not confirm elevated subjective cognitive complaints in a group of Type 1 and Type 2 diabetes patients, as might be expected given the observed elevated rates of mild cognitive dysfunction in patients with diabetes. Self-reported cognitive failure appears largely determined by depressive symptomatology. Therefore, affective status should be included in any cognitive assessment procedure.

Monitoring health related quality of life in adolescents with diabetes: a review of measures

Particularly in chronic conditions, monitoring health related quality of life (HRQoL) of adolescents in clinical practice is increasingly advocated. We set out to identify and review the clinical utility of available generic and diabetes specific HRQoL questionnaires suitable for use in adolescents with type 1 diabetes. Four generic and five diabetes specific questionnaires were identified and evaluated. The responsiveness of most instruments warrants further research and standardisation of HRQoL measurement should be sought to facilitate comparisons across centres and countries. The PedsQL and the KINDL-R appear, at this time, to be the most suitable instruments.

Associations between depressive symptoms and insulin resistance: the Hoorn Study

AIMS/HYPOTHESIS

The association between depression and insulin resistance has been investigated in only a few studies, with contradictory results reported. The aim of this study was to determine whether the association between symptoms of depression and insulin resistance varies across glucose tolerance status and between men and women.

SUBJECTS AND METHODS

Cross-sectional data from a population-based cohort study in Hoorn, a medium-sized town in the Netherlands, were analysed. The study sample consisted of 541 men and women aged 55-75 years, of whom 260 had NGT, 164 had IGT and 117 had established type 2 diabetes mellitus. Main outcome measures were insulin resistance defined by the homeostasis model assessment for insulin resistance (HOMA-IR) and symptoms of depression using the Centre for Epidemiologic Studies Depression Scale (CES-D).

RESULTS

In the total sample, we found a weak positive correlation between the depressive symptoms CED-D scores and HOMA-IR scores (r (s) = 0.156, p < 0.001). Even weaker associations were found in subjects with NGT (r (s) = 0.041, p=0.509), in subjects with IGT (r (s) = 0.112, p = 0.160) and in subjects with type 2 diabetes (r (s) = 0.007, p = 0.942). The association between depressive symptoms and insulin resistance was similar for men and women.

CONCLUSIONS/INTERPRETATION

We found only weak associations between depressive symptoms and insulin resistance, which did not differ among different glucose metabolism subgroups or between men and women.

Depression as a risk factor for the onset of type 2 diabetes mellitus. A meta-analysis

AIMS/HYPOTHESIS

Evidence strongly suggests that depression and type 2 diabetes are associated, but the direction of the association is still unclear. Depression may occur as a consequence of having diabetes, but may also be a risk factor for the onset of type 2 diabetes. This study examined the latter association by reviewing the literature and conducting a meta-analysis of longitudinal studies on this topic.

METHODS

Medline and PsycInfo were searched for articles published up to January 2005. All studies that examined the relationship between depression and the onset of type 2 diabetes were included. Pooled relative risks were calculated using fixed and random effects models. To explore sources of heterogeneity between studies, subgroup analyses and meta-regression analyses were performed.

RESULTS

Nine studies met our inclusion criteria for this meta-analysis. The pooled relative risk was 1.26 (1.13-1.39) using the fixed effects model and 1.37 (1.14-1.63) using the random effects model. Heterogeneity between studies could not be explained by (1) whether studies controlled for undetected diabetes at baseline; (2) the method of diabetes assessment at follow-up; (3) the baseline overall risk of diabetes in the study population; and (4) follow-up duration.

CONCLUSIONS/INTERPRETATION

Depressed adults have a 37% increased risk of developing type 2 diabetes mellitus. The pathophysiological mechanisms underlying this relationship are still unclear and warrant further research. A randomised controlled study is needed to test whether effective prevention or treatment of depression can reduce the incidence of type 2 diabetes and its health consequences.

Nurses' recognition and registration of depression, anxiety and diabetes-specific emotional problems in outpatients with diabetes mellitus

OBJECTIVE

The aim of this study was to investigate how often emotional problems were recognized and registered by diabetes nurses.

METHODS

We studied medical charts and questionnaire data of 112 diabetes patients. The hospital anxiety, depression scale and the problem areas in diabetes survey were used to measure anxiety, depression and diabetes-specific emotional distress.

RESULTS

In patients with moderate to severe levels of anxiety or depression, the presence of an emotional problem was recorded in the medical chart in 20-25% of the cases. The registration-rate of diabetes-specific emotional distress was also found to be low, ranging from 0% (treatment-related problems) to 29% (diabetes-related emotional problems).

CONCLUSION

Registration-rates of emotional problems by diabetes nurses were found to be low, but quite similar to detection rates of physicians and nurses in studies with non-diabetic samples.

PRACTICE IMPLICATIONS

These findings suggest that recognition-rates of emotional problems in diabetes patients need to be increased. Future studies should investigate whether recognition and subsequent treatment of emotional problems in diabetes patients can be facilitated by utilizing validated, standardized self-report questionnaires.

Serious diabetes-specific emotional problems and depression in a Croatian-Dutch-English Survey from the European Depression in Diabetes [EDID] Research Consortium

It has been hypothesized that coverage of diabetes-specific issues (e.g. coping with complications, incapacity, pain) during psychotherapy may optimize the likelihood of treatment success for depression in patients with diabetes. However, it is still unclear how often depression is confounded by diabetes-specific emotional problems. We aim to determine the levels of diabetes-specific emotional problems in diabetic individuals with high versus low levels of depression in a sample of 539 outpatients with diabetes (202 Dutch, 185 Croatian and 152 English). Subjects completed the Center for Epidemiological Studies Depression and the Problem Areas in Diabetes scales. Percentages of patients with high depression scores were: 39 and 34% (Croatian men and women), 19 and 21% (Dutch men and women), 19 and 39% (English men and women). Moreover, 79% (Croatian), 47% (Dutch) and 41% (English) of the patients with a severe depression score reported to have four or more serious diabetes-specific emotional problems. For patients with low depression scores, these percentages were: 29% (Croatian), 11% (Dutch) and 1% (English). Serious diabetes-specific emotional problems are particularly prevalent in depressed diabetes patients. Randomized controlled trials are warranted to test whether coverage of diabetes-specific issues during psychotherapy can further improve the treatment of depression in diabetes.

Fat food for a bad mood. Could we treat and prevent depression in Type 2 diabetes by means of omega-3 polyunsaturated fatty acids? A review of the evidence

AIMS

Evidence strongly suggests that depression is a common complication of Type 2 diabetes mellitus. However, there is considerable room to improve the effectiveness of pharmacological antidepressant agents, as in only 50-60% of the depressed subjects with diabetes does pharmacotherapy lead to remission of depression. The aim of the present paper was to review whether polyunsaturated fatty acids (PUFA) of the omega-3 family could be used for the prevention and treatment of depression in Type 2 diabetes.

METHODS

MEDLINE database and published reference lists were used to identify studies that examined the associations between omega-3 PUFA and depression. To examine potential side-effects, such as on glycaemic control, studies regarding the use of omega-3 supplements in Type 2 diabetes were also reviewed.

RESULTS

Epidemiological and clinical studies suggest that a high intake of omega-3 PUFA protects against the development of depression. There is also some evidence that a low intake of omega-3 is associated with an increased risk of Type 2 diabetes, but the results are less conclusive. Results from randomized controlled trials in non-diabetic subjects with major depression show that eicosapentaenoic acid is an effective adjunct treatment of depression in diabetes, while docosahexanoic acid is not. Moreover, consumption of omega-3 PUFA reduces the risk of cardiovascular disease and may therefore indirectly decrease depression in Type 2 diabetes, via the reduction of cardiovascular complications.

CONCLUSIONS

Supplementation with omega-3 PUFA, in particular eicosapentaenoic acid, may be a safe and helpful tool to reduce the incidence of depression and to treat depression in Type 2 diabetes. Further studies are now justified to test these hypotheses in patients with Type 2 diabetes.

Are factor analytical techniques used appropriately in the validation of health status questionnaires? A systematic review on the quality of factor analysis of the SF-36

Factor analysis is widely used to evaluate whether questionnaire items can be grouped into clusters representing different dimensions of the construct under study. This review focuses on the appropriate use of factor analysis. The Medical Outcomes Study Short Form-36 (SF-36) is used as an example. Articles were systematically searched and assessed according to a number of criteria for appropriate use and reporting. Twenty-eight studies were identified: exploratory factor analysis was performed in 22 studies, confirmatory factor analysis was performed in five studies and in one study both were performed. Substantial shortcomings were found in the reporting and justification of the methods applied. In 15 of the 23 studies in which exploratory factor analysis was performed, confirmatory factor analysis would have been more appropriate. Cross-validation was rarely performed. Presentation of the results and conclusions was often incomplete. Some of our results are specific for the SF-36, but the finding that both the application and the reporting of factor analysis leaves much room for improvement probably applies to other health status questionnaires as well. Optimal reporting and justification of methods is crucial for correct interpretation of the results and verification of the conclusions. Our list of criteria may be useful for journal editors, reviewers and researchers who have to assess publications in which factor analysis is applied.

Rates and risks for co-morbid depression in patients with Type 2 diabetes mellitus: results from a community-based study

AIMS/HYPOTHESIS

There is accumulating evidence that depression is common in people with Type 2 diabetes. However, most prevalence-studies are uncontrolled and could also be inaccurate from selection-bias, as they are conducted in specialized treatment settings. We studied the prevalence and risk factors of co-morbid depression in a community-based sample of older adults, comparing Type 2 diabetic patients with healthy control subjects.

METHODS

A large (n=3107) community-based study in Dutch adults (55-85 years of age) was conducted. Pervasive depression was defined as a CES-D score greater than 15. Diagnosis of Type 2 diabetes was obtained from self-reports and data from general practitioners.

RESULTS

A number of 216 patients (7%) were identified as having Type 2 diabetes. The prevalence of pervasive depression was increased in people with Type 2 diabetes and co-morbid chronic disease (20%) but not in patients with Type 2 diabetes only (8%), compared with the healthy control subjects (9%). Regression analyses in diabetic patients yielded that being single, being female, having functional limitations, receiving instrumental support and having an external locus of control were associated with higher levels of depression.

CONCLUSIONS/INTERPRETATION

The Results suggest that the prevalence of pervasive depression is increased in patients with Type 2 diabetes and co-morbid disease(s), but not in patients with Type 2 diabetes only. Functional limitations that often accompany co-morbid chronic disease could play an essential role in the development of depression in Type 2 diabetes. These findings can enable clinicians and researchers to identify high-risk groups and set up prevention and treatment programs.

Continuous intraperitoneal insulin infusion in patients with 'brittle' diabetes: favourable effects on glycaemic control and hospital stay

AIMS

To evaluate the effects of continuous intraperitoneal insulin infusion (CIPII) using implantable pumps on glycaemic control and duration of hospital stay in poorly controlled 'brittle' Dutch diabetes patients, and to assess their current quality of life.

METHODS

Thirty-three patients were included. Glycaemic control was retrospectively assessed with HbA(1c) levels acquired before implantation, 1 year later and at long-term follow up of 58 months. Duration of hospital stay the year before and the year following first implantation was extracted from hospital records. Determinants of long-term glycaemic response were sought. Self-report questionnaires were administered at 58 months follow-up only, to assess current psychopathology and quality of life.

RESULTS

Mean HbA(1c) decreased from 10.0 +/- 2.3% to 9.0 +/- 1.8% (P = 0.039) 1 year after implantation and stabilized at 9.0 +/- 1.6% (P = 0.023) during long-term follow-up. Median number of hospital days in the 20 patients suffering from hospital admission before implantation decreased from 45 the year before implantation to 13 the year after (P = 0.005). Patients with a higher baseline HbA(1c) showed a larger long-term response (P < 0.001). Relatively low levels for quality of life were found, as well as a higher than expected number of patients with psychiatric symptoms.

CONCLUSIONS

CIPII proved effective in complex patients with a history of poor control and hospital admission. Despite a substantial long-term improvement in glycaemic control and diminished hospital stay, normal levels of glycaemic control and quality of life were not attained.

Patients' Evaluation of the Quality of Diabetes Care (PEQD): development and validation of a new instrument

OBJECTIVES

To develop a brief measure of patients' evaluation of the quality of diabetes care and to study predictors of consumers' rating of the quality of diabetes care.

DESIGN

A prospective design.

SUBJECTS

176 adults with type 1 (39%) or type 2 (61%) diabetes.

MAIN MEASURES

Demographic variables, HbA1c, number of diabetes complications, satisfaction with diabetes care, diabetes related distress, and fear of hypoglycaemia were assessed by self-report. In addition, satisfaction with diabetes care and evaluations about quality of the care were measured at 16 month follow up. Statistical analysis comprised principal component analyses, Cronbach's alpha, t tests, Pearson's correlation, and linear regression analyses.

RESULTS

Results in the literature were used to develop the 14 items of the Patients' Evaluation of the Quality of Diabetes Care (PEQD) scale, assessing the most important aspects of the quality of diabetes care as delivered by the specialist in internal medicine (internist) and the diabetes nurse specialist (DNS). Two principal components analyses (internist/DNS) both yielded one 14 item factor with a high internal consistency. Satisfaction with diabetes care, fewer diabetes related complications, fewer treatment related problems, and a low level of worries about hypoglycaemia were predictors of a more positive evaluation of diabetes care delivered by the internist. Sociodemographic variables were not related to the patients' evaluations of the quality of diabetes care.

CONCLUSIONS

The PEQD comprises different aspects of quality of diabetes care and can be regarded as a suitable instrument for evaluating patients' judgements about the quality of their care.

Monitoring of psychological well-being in outpatients with diabetes: effects on mood, HbA(1c), and the patient's evaluation of the quality of diabetes care: a randomized controlled trial

OBJECTIVE

To investigate whether monitoring and discussing psychological well-being in outpatients with diabetes improves mood, glycemic control, and the patient's evaluation of the quality of diabetes care.

RESEARCH DESIGN AND METHODS

This study was a randomized controlled trial of 461 outpatients with diabetes who were randomly assigned to standard care or to the monitoring condition. In the latter group, the diabetes nurse specialist assessed and discussed psychological well-being with the patient (with an interval of 6 months) in addition to standard care. The computerized Well-being Questionnaire was used for this purpose. Primary outcomes were mood, HbA(1c), and the patient's evaluation of the quality of diabetes care at 1-year follow-up. The number of referrals to the psychologist was analyzed as a secondary outcome. Intention-to-treat analysis was used.

RESULTS

The monitoring group reported better mood compared with the standard care group, as indicated by significantly lower negative well-being and significantly higher levels of energy, higher general well-being, better mental health, and a more positive evaluation of the quality of the emotional support received from the diabetes nurse. The two groups did not differ for HbA(1c) or in their overall evaluation of the quality of diabetes care. In the monitoring condition, significantly more subjects were referred to the psychologist.

CONCLUSIONS

Monitoring and discussing psychological well-being as part of routine diabetes outpatient care had favorable effects on the mood of patients but did not affect their HbA(1c). Our results support the recommendation to monitor psychological well-being in patients with diabetes.

Association between symptoms of depression and glycaemic control may be unstable across gender

AIMS

Lloyd and colleagues (Diabetic Med 2000; 17, 198-202) have described an association between poor glycaemic control and moderate to severe depression in male but not in female diabetes patients. However, the validity of this study may be limited by its small sample size and the influence of uncontrolled confounders. Therefore, we set out to replicate this study by investigating the associations between depression and glycaemic control in larger samples, while controlling for potential confounders.

METHODS

Out-patients with diabetes (n = 174) and 1437 patient members of the Dutch Diabetes Association (DDA) completed the Hospital Anxiety and Depression Scale. Demographic and clinical characteristics were obtained using medical records (out-patients) or self-report (DDA).

RESULTS

After controlling for number of complications, years of education and body mass index, depression showed significant, low positive correlations with HbA(1c) in three of the four female samples and in one of the four male samples. Only for out-patients with Type 2 diabetes was the correlation between HbA(1c) and depression significantly higher for women when compared with men (0.19 vs. 0.04; P = 0.02).

CONCLUSIONS

The association between depression and HbA1c may be stronger in women with Type 2 diabetes. Oestrogen levels and self-care behaviours may play a mediating role in this association. Further research is required before we can conclude that the association between symptoms of depression and glycaemic control differs across gender. Diabet. Med. 18, 595-598 (2001)

Diabetes-related emotional distress in Dutch and U.S. diabetic patients: cross-cultural validity of the problem areas in diabetes scale

OBJECTIVE

To examine the cross-cultural validity of the Problem Areas in Diabetes Scale (PAID) in Dutch and U.S. diabetic patients.

RESEARCH DESIGN AND METHODS

A total of 1,472 Dutch people with diabetes completed the PAID along with other self-report measures of affect. Statistics covered Cronbach's alpha, exploratory factor analysis (EFA), and confirmatory factor analysis (CFA), Pearson's product-moment correlation, and t tests. Psychometric properties of PAID were compared for Dutch and U.S. diabetic patients.

RESULTS

Internal consistency of the Dutch PAID was high and stable across sex and type of diabetes. Test-retest reliability was high. Principal component analyses confirmed 1 general 20-item factor, whereas EFA identified 4 new subdimensions: negative emotions, treatment problems, food-related problems, and lack of social support. These dimensions were confirmed with CFA and were replicated in the U.S. sample. The PAID and its subscales demonstrated moderate to high associations in the expected direction with other measures of affect. Dutch and U.S. subjects reported having the same problem areas, with U.S. patients reporting higher emotional distress levels both in type 1 and type 2 diabetes.

CONCLUSIONS

The Dutch and U.S. 20-item PAID appeared to be psychometrically equivalent, which allowed for cross-cultural comparisons.

Psychological distress two years after diagnosis of breast cancer: frequency and prediction

The present prospective study aimed at (1) investigating the frequency of high levels of psychological distress in women with early-stage breast cancer almost two years after diagnosis and (2) identifying characteristics associated with long-term distress. One hundred and seventy women participated on two occasions. Two months after surgery, patients completed questionnaires measuring psychosocial variables (e.g., stressful life-events, health complaints, sleep problems, social support, subjective distress, personality factors), demographic and biomedical variables (e.g., TNM status, type of surgery). At the second measurement, subjective distress was assessed for a second time by means of the Impact of Events Scale (IES). Almost two years after diagnosis, 16% of the women reported a high level of psychological distress as measured by the Intrusion scale (IES). Best predictors of a high level of distress were: intrusive thoughts about the disease, trait-anxiety, health complaints and problems with sleeping. No significant association was found between previous life-events, social support or biomedical variables and levels of distress.

Diabetes Fear of Injecting and Self-Testing Questionnaire: a psychometric evaluation

OBJECTIVE

To study the psychometric properties of the Diabetes Fear of Injecting and Self-Testing Questionnaire (D-FISQ).

RESEARCH DESIGN AND METHODS

Two groups of patients were studied. Sample A consisted of 252 insulin-treated diabetes patients. Sample B incorporated 24 insulin-treated patients with high scores (> or = 95th percentile) on the D-FISQ. Test-retest correlations were assessed in both samples. Discriminant and convergent validity of the D-FISQ were assessed with questionnaires concerning fear of hypoglycemia, trait anxiety, and fear of bodily injury, illness, or death. To evaluate criterion-related validity, sample B participated in a behavioral avoidance test (BAT), in which the current level of avoidance of either self-injecting or self-testing was determined. Exploratory factor analysis (EFA) was performed to study whether 2 factors (fear of self-injecting [FSI] and fear of self-testing [FST]) could be detected.

RESULTS

Test-retest correlations ranged from 0.50 to 0.68 (P < 0.001). Correlations between D-FISQ and fear of hypoglycemia, trait anxiety, and fear of bodily injury, illness, or death ranged from 0.28 to 0.45 (P < 0.001). Patients who refused to do a BAT for self-injecting or self-testing had higher scores on FSI (P = 0.095) and FST (P = 0.01). EFA yielded 2 separate factors, FSI and FST.

CONCLUSIONS

Results from this study support reliability and validity of the D-FISQ, a self-report instrument that can be used for both clinical and research purposes.

The well-being questionnaire: evidence for a three-factor structure with 12 items (W-BQ12)

BACKGROUND

The Well-being Questionnaire (W-BQ) has been designed to measure psychological well-being in people with a chronic somatic illness and is recommended by the World Health Organization for widespread use. However, studies into the factor structure of this instrument are still limited and their findings are inconsistent. This study aimed to investigate the factor structure of the Dutch version of the W-BQ.

METHODS

A cross-validation design was used. A total of 1472 people with diabetes completed the W-BQ and were randomly assigned to group A or B. In group A (N = 736), exploratory factor analyses were conducted. Group B (N = 736) was split up into four subgroups of male or female patients with type 1 or type 2 diabetes. In these subgroups, confirmatory factor analyses were employed to test the model(s) developed in group A and the two models described in the literature (four-factor model with 22 items and a three-factor model with 12 items).

RESULTS

Exploratory factor analyses yielded a three-factor model with 21 items (negative well-being, energy and positive well-being). In the subgroups of group B confirmatory factor analyses only accepted the three-factor model with 12 items. This factor solution was stable across gender, type of diabetes and level of education.

CONCLUSIONS

The best description of the factor structure of the Dutch translation of the W-BQ was given by a three-factor solution with 12 items (W-BQ12), measuring positive well-being (four items), negative well-being (four items) and energy (four items).

The 12-item well-being questionnaire. An evaluation of its validity and reliability in Dutch people with diabetes

OBJECTIVE

The objective of this study was to investigate the validity and reliability of the short-form 12-Item Well-Being Questionnaire (W-BQ12). The 12 items were used to construct the three 4-item subscales Negative Well-Being (NWB), Energy (ENE), and Positive Well-Being (PWB), and the 12-item overall scale General Well-Being (GWB).

RESEARCH DESIGN AND METHODS

A total of 1,472 patients with diabetes completed the W-BQ12, the Hospital Anxiety and Depression scale, and the State Trait Anxiety Inventory. Statistics covered Cronbach's alpha, Pearson's correlation, t tests, and logistic regression. Test-retest reliability was studied in a sample of 202 patients who twice completed the W-BQ12, which was supplemented with the Center for Epidemiological Studies Depression scale and the Short Form (SF)-36 Health Survey.

RESULTS

Of the tested subjects, 739 were defined as having type 1 diabetes and 701 as having type 2 diabetes. Cronbach's alpha proved to be high and stable across sex and type of diabetes for all W-BQ12 scales. Test-retest reliability ranged from 0.66 (PWB) to 0.83 (GWB), with a mean interval of 66 +/- 14 days. Convergent validity of the W-BQ12 scales was supported by high correlations with other measures of affect. Of all scales of the first measurement, ENE proved to have the strongest association with self-reported chronic fatigue. NWB and trait anxiety both had the strongest associations with self-reported depression and current treatment by a psychologist/psychiatrist.

CONCLUSIONS

The W-BQ12 appeared to be a reliable and valid measure of psychological well-being. This short instrument is easy to administer and may be considered a useful tool for both clinicians and researchers to assess the psychological well-being of patients with diabetes.

Factor structure of the Disability and Impact Profile in patients with multiple sclerosis

The Disability and Impact Profile (DIP) is used for the measurement of quality of life in multiple sclerosis (MS) patients. Data from 211 persons with definite MS from Belgium, Denmark and the Netherlands were used to address three questions. To what extent do the impairment ratings and their complementary weighted scores share common variance? What is the factor structure of the weighted scores? To what extent do disease-related information and information from psychological questionnaires offer concurrent validity for the factors? Correlations between impairment ratings and the weighted item scores were high; for most items the complementary ratings of impact do not supplement information provided by impairment ratings. The DIP weighted scores can be represented to some extent by three independent dimensions: a motor (skeletal movement) or displacement ability factor, a factor relating to sensory-cognitive intactness and a psychological well-being factor. A two-factor solution provides a first factor identical to that of the three-factor solution and a second factor representing psychological well-being. The two factors correlate well with instruments measuring disability and with satisfaction versus emotional distress. Provisional scales based on the factors were constructed.

[Straying in the methodology. II. Bias introduced by questionnaires]

Some characteristics of self-report questionnaires can result in bias in responding. When a test item or a questionnaire is biased, the observed scores form an imprecise measurement of reality as a consequence of systematic errors of measurement. Causes of such bias are: unclear instructions, vague wording of the test items, culture-bound item content, suggestive questions, framing of questions, social desirability of certain answers, faking good, faking bad and the recall bias.

Psychological functioning in primary progressive versus secondary progressive multiple sclerosis

Psychological functioning in two types of multiple sclerosis (MS) patients is assessed: primary progressive (PP) and secondary progressive (SP) patients. On the basis of differences in clinical course and underlying pathology we hypothesized that primary progressive patients and secondary progressive patients might have different psychological functioning. Seventy patients treated in an MS centre were examined cross-sectionally. Forty had an SP course of MS and 30 a PP course. The 33 male and 37 female patients had a mean age of 48.4 years (SD 11.2) and mean age of onset of MS of 30.7 years (SD 11.1). Patients completed questionnaires measuring among others the following aspects of psychological functioning: depression (BDI, SCL-90), anxiety (STAI, SCL-90), agoraphobia (SCL-90), somatic complaints (SCL-90), hostility (SCL-90) and attitude towards handicap (GHAS). Patients with a PP-MS scored significantly better on 5 out of 14 subscales than patients with SP-MS (p < .05). On the basis of our operationalizations of psychological functioning, the findings support the conclusion that on average 18 years after diagnosis of MS, amongst patients attending an MS unit, primary progressive patients were found to have better psychological functioning.

A comparison of the standard and the computerized versions of the Well-being Questionnaire (WBQ) and the Diabetes Treatment Satisfaction Questionnaire (DTSQ)

In the present study, the equivalence of paper and pencil assessment versus computer assessment of two self-administered questionnaires was investigated by means of a randomized cross-over design. Therefore, 105 out-patients with diabetes were invited to participate; 76 patients completed both the computer and the paper and pencil version of the Well-being Questionnaire (WBQ) and the Diabetes Treatment Satisfaction Questionnaire (DTSQ) in a randomized order, with a mean interval of 7 days. The scales showed high test-retest correlations and the means, dispersions, kurtosis and skewness were found to be approximately the same in both versions. In both modes of assessment, the depression and the energy scale proved to be sensitive for carry-over effects, resulting in better well-being scores at the second measurement. Almost all subjects reported that using the personal computer in the realization of a questionnaire was easy. It is concluded that the paper and pencil and the computerized versions of the WBQ and DTSQ can be considered equivalent. Therefore, the norms and cut-off scores obtained from paper and pencil assessments can be used in computerized versions of the WBQ and DTSQ and vice versa.