Why are there discrepancies between depressed patients' Global Rating of Change and scores on the Patient Health Questionnaire depression module? A qualitative study of primary care in England

Investigating the PHQ-9 With Mokken Scale Analysis and Cognitive Interviews

Scores on the Patient Health Questionnaire-9 (PHQ-9) are frequently used to assess depression both in research and in clinical practice. The aim was to examine the validity of the PHQ-9 sum score by using Mokken scale analysis (Study I) and cognitive interviews (Study II) on the Icelandic version of PHQ-9. A primary care sample of 618 individuals was used in Study I. The results indicate that the PHQ-9 items are not close enough to perfectly unidimensional for their sum score to accurately order people on the depression severity dimension. In Study II, the sample consisted of 53 individuals, with 28 having a history of depression and 25 not. The findings reveal a number of issues concerning respondents' use of the PHQ-9. No systematic differences were found in the results of the two groups. The PHQ-9 sum score should thus be interpreted and used with great care. We provide scale revision recommendations to improve the quality of PHQ-9.

Patient-reported outcome measures for monitoring primary care patients with depression: the PROMDEP cluster RCT and economic evaluation

Background

Guidelines on the management of depression recommend that practitioners use patient-reported outcome measures for the follow-up monitoring of symptoms, but there is a lack of evidence of benefit in terms of patient outcomes.

Objective

To test using the Patient Health Questionnaire-9 questionnaire as a patient-reported outcome measure for monitoring depression, training practitioners in interpreting scores and giving patients feedback.

Design

Parallel-group, cluster-randomised superiority trial; 1 : 1 allocation to intervention and control.

Setting

UK primary care (141 group general practices in England and Wales).

Inclusion criteria

Patients aged ≥ 18 years with a new episode of depressive disorder or symptoms, recruited mainly through medical record searches, plus opportunistically in consultations.

Exclusions

Current depression treatment, dementia, psychosis, substance misuse and risk of suicide.

Intervention

Administration of the Patient Health Questionnaire-9 questionnaire with patient feedback soon after diagnosis, and at follow-up 10-35 days later, compared with usual care.

Primary outcome

Beck Depression Inventory, 2nd edition, symptom scores at 12 weeks.

Secondary outcomes

Beck Depression Inventory, 2nd edition, scores at 26 weeks; antidepressant drug treatment and mental health service contacts; social functioning (Work and Social Adjustment Scale) and quality of life (EuroQol 5-Dimension, five-level) at 12 and 26 weeks; service use over 26 weeks to calculate NHS costs; patient satisfaction at 26 weeks (Medical Informant Satisfaction Scale); and adverse events.

Sample size

The original target sample of 676 patients recruited was reduced to 554 due to finding a significant correlation between baseline and follow-up values for the primary outcome measure.

Randomisation

Remote computerised randomisation with minimisation by recruiting university, small/large practice and urban/rural location.

Blinding

Blinding of participants was impossible given the open cluster design, but self-report outcome measures prevented observer bias. Analysis was blind to allocation.

Analysis

Linear mixed models were used, adjusted for baseline depression, baseline anxiety, sociodemographic factors, and clustering including practice as random effect. Quality of life and costs were analysed over 26 weeks.

Qualitative interviews

Practitioner and patient interviews were conducted to reflect on trial processes and use of the Patient Health Questionnaire-9 using the Normalization Process Theory framework.

Results

Three hundred and two patients were recruited in intervention arm practices and 227 patients were recruited in control practices. Primary outcome data were collected for 252 (83.4%) and 195 (85.9%), respectively. No significant difference in Beck Depression Inventory, 2nd edition, score was found at 12 weeks (adjusted mean difference -0.46, 95% confidence interval -2.16 to 1.26). Nor were significant differences found in Beck Depression Inventory, 2nd Edition, score at 26 weeks, social functioning, patient satisfaction or adverse events. EuroQol-5 Dimensions, five-level version, quality-of-life scores favoured the intervention arm at 26 weeks (adjusted mean difference 0.053, 95% confidence interval 0.013 to 0.093). However, quality-adjusted life-years over 26 weeks were not significantly greater (difference 0.0013, 95% confidence interval -0.0157 to 0.0182). Costs were lower in the intervention arm but, again, not significantly (-£163, 95% confidence interval -£349 to £28). Cost-effectiveness and cost-utility analyses, therefore, suggested that the intervention was dominant over usual care, but with considerable uncertainty around the point estimates. Patients valued using the Patient Health Questionnaire-9 to compare scores at baseline and follow-up, whereas practitioner views were more mixed, with some considering it too time-consuming.

Conclusions

We found no evidence of improved depression management or outcome at 12 weeks from using the Patient Health Questionnaire-9, but patients' quality of life was better at 26 weeks, perhaps because feedback of Patient Health Questionnaire-9 scores increased their awareness of improvement in their depression and reduced their anxiety. Further research in primary care should evaluate patient-reported outcome measures including anxiety symptoms, administered remotely, with algorithms delivering clear recommendations for changes in treatment.

Study registration

This study is registered as IRAS250225 and ISRCTN17299295.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/42/02) and is published in full in Health Technology Assessment; Vol. 28, No. 17. See the NIHR Funding and Awards website for further award information.

Applying contrastive pre-training for depression and anxiety risk prediction in type 2 diabetes patients based on heterogeneous electronic health records: a primary healthcare case study

OBJECTIVE

Due to heterogeneity and limited medical data in primary healthcare services (PHS), assessing the psychological risk of type 2 diabetes mellitus (T2DM) patients in PHS is difficult. Using unsupervised contrastive pre-training, we proposed a deep learning framework named depression and anxiety prediction (DAP) to predict depression and anxiety in T2DM patients.

MATERIALS AND METHODS

The DAP model consists of two sub-models. Firstly, the pre-trained model of DAP used unlabeled discharge records of 85 085 T2DM patients from the First Affiliated Hospital of Nanjing Medical University for unsupervised contrastive learning on heterogeneous electronic health records (EHRs). Secondly, the fine-tuned model of DAP used case-control cohorts (17 491 patients) selected from 149 596 T2DM patients' EHRs in the Nanjing Health Information Platform (NHIP). The DAP model was validated in 1028 patients from PHS in NHIP. Evaluation included receiver operating characteristic area under the curve (ROC-AUC) and precision-recall area under the curve (PR-AUC), and decision curve analysis (DCA).

RESULTS

The pre-training step allowed the DAP model to converge at a faster rate. The fine-tuned DAP model significantly outperformed the baseline models (logistic regression, extreme gradient boosting, and random forest) with ROC-AUC of 0.91±0.028 and PR-AUC of 0.80±0.067 in 10-fold internal validation, and with ROC-AUC of 0.75 ± 0.045 and PR-AUC of 0.47 ± 0.081 in external validation. The DCA indicate the clinical potential of the DAP model.

CONCLUSION

The DAP model effectively predicted post-discharge depression and anxiety in T2DM patients from PHS, reducing data fragmentation and limitations. This study highlights the DAP model's potential for early detection and intervention in depression and anxiety, improving outcomes for diabetes patients.

Suicidal Thinking Among Patients With Spinal Conditions in South Korea: A Population-Based Cross-Sectional Study

OBJECTIVE

Chronic pain increases the risk of suicide because it is often accompanied by depressive symptoms. However, the existing information regarding suicidal thinking in patients with chronic pain such as spinal conditions is insufficient. We aimed to examine the prevalence of suicidal thinking and the factors associated with it among patients with spinal conditions.

METHODS

Data from the National Health Insurance Service database in South Korea were used in this population-based, cross-sectional study, and 2.5% of adult patients diagnosed with spinal conditions (low back pain and/or neck pain) between 2018 and 2019 were selected using a stratified random sampling technique. Patient Health Questionnaire-9 was used to determine the presence of suicidal thoughts and depressive symptoms.

RESULTS

33,171 patients with spinal conditions were included in this study. Among them, 5.9% had suicidal thinking and 20.7% had depressive symptoms. In the multivariable logistic regression model, old age, male sex, and employment were associated with a decreased prevalence of suicidal thinking. Current smokers, previous smokers, medical aid program recipients, and patients with mild-to-moderate or severe disability showed increased suicidal thinking. Underlying depression, bipolar disorder, insomnia disorder, and substance abuse were also associated with increased suicidal thinking.

CONCLUSION

In South Korea, 5.9% and 20.7% of patients with spinal conditions had suicidal thoughts and depressive symptoms, respectively. Some factors were associated with an increased prevalence of suicidal thoughts among patients with spinal conditions. Our results suggest that screening for these factors can help prevent suicide in patients with spinal conditions.

Depression, anxiety and PTSD symptoms before and during the COVID-19 pandemic in the UK

BACKGROUND

The impact of the coronavirus disease 2019 (COVID-19) pandemic on mental health is still being unravelled. It is important to identify which individuals are at greatest risk of worsening symptoms. This study aimed to examine changes in depression, anxiety and post-traumatic stress disorder (PTSD) symptoms using prospective and retrospective symptom change assessments, and to find and examine the effect of key risk factors.

METHOD

Online questionnaires were administered to 34 465 individuals (aged 16 years or above) in April/May 2020 in the UK, recruited from existing cohorts or via social media. Around one-third (n = 12 718) of included participants had prior diagnoses of depression or anxiety and had completed pre-pandemic mental health assessments (between September 2018 and February 2020), allowing prospective investigation of symptom change.

RESULTS

Prospective symptom analyses showed small decreases in depression (PHQ-9: -0.43 points) and anxiety [generalised anxiety disorder scale - 7 items (GAD)-7: -0.33 points] and increases in PTSD (PCL-6: 0.22 points). Conversely, retrospective symptom analyses demonstrated significant large increases (PHQ-9: 2.40; GAD-7 = 1.97), with 55% reported worsening mental health since the beginning of the pandemic on a global change rating. Across both prospective and retrospective measures of symptom change, worsening depression, anxiety and PTSD symptoms were associated with prior mental health diagnoses, female gender, young age and unemployed/student status.

CONCLUSIONS

We highlight the effect of prior mental health diagnoses on worsening mental health during the pandemic and confirm previously reported sociodemographic risk factors. Discrepancies between prospective and retrospective measures of changes in mental health may be related to recall bias-related underestimation of prior symptom severity.

Prognostic factors and effect modifiers for personalisation of internet-based cognitive behavioural therapy among university students with subthreshold depression: A secondary analysis of a factorial trial

BACKGROUND

Internet-cognitive behavioural therapy (iCBT) for depression can include multiple components. This study explored depressive symptom improvement prognostic factors (PFs) and effect modifiers (EMs) for five common iCBT components including behavioural activation, cognitive restructuring, problem solving, self-monitoring, and assertion training.

METHODS

We used data from a factorial trial of iCBT for subthreshold depression among Japanese university students (N = 1093). The primary outcome was the change in PHQ-9 scores at 8 weeks from baseline. Interactions between each component and various baseline characteristics were estimated using a mixed-effects model for repeated measures. We calculated multiplicity-adjusted p-values at 5 % false discovery rate using the Benjamini-Hochberg procedure.

RESULTS

After multiplicity adjustment, the baseline PHQ-9 total score emerged as a PF and exercise habits as an EM for self-monitoring (adjusted p-values <0.05). The higher the PHQ-9 total score at baseline (range: 5-14), the greater the decrease after 8 weeks. For each 5-point increase at baseline, the change from baseline to 8 weeks was bigger by 2.8 points. The more frequent the exercise habits (range: 0-2 points), the less effective the self-monitoring component. The difference in PHQ-9 change scores between presence or absence of self-monitoring was smaller by 0.94 points when the participant exercised one level more frequently. Additionally, the study suggested seven out of 36 PFs and 14 out of 160 EMs examined were candidates for future research.

LIMITATIONS

Generalizability is limited to university students with subthreshold depression.

CONCLUSIONS

These results provide some helpful information for the future development of individualized iCBT algorithms for depression.

Patient characteristics associated with retrospectively self-reported treatment outcomes following psychological therapy for anxiety or depressive disorders - a cohort of GLAD study participants

BACKGROUND

Progress towards stratified care for anxiety and depression will require the identification of new predictors. We collected data on retrospectively self-reported therapeutic outcomes in adults who received psychological therapy in the UK in the past ten years. We aimed to replicate factors associated with traditional treatment outcome measures from the literature.

METHODS

Participants were from the Genetic Links to Anxiety and Depression (GLAD) Study, a UK-based volunteer cohort study. We investigated associations between retrospectively self-reported outcomes following therapy, on a five-point scale (global rating of change; GRC) and a range of sociodemographic, clinical and therapy-related factors, using ordinal logistic regression models (n = 2890).

RESULTS

Four factors were associated with therapy outcomes (adjusted odds ratios, OR). One sociodemographic factor, having university-level education, was associated with favourable outcomes (OR = 1.37, 95%CI: 1.18, 1.59). Two clinical factors, greater number of reported episodes of illness (OR = 0.95, 95%CI: 0.92, 0.97) and higher levels of personality disorder symptoms (OR = 0.89, 95%CI: 0.87, 0.91), were associated with less favourable outcomes. Finally, reported regular use of additional therapeutic activities was associated with favourable outcomes (OR = 1.39, 95%CI: 1.19, 1.63). There were no statistically significant differences between fully adjusted multivariable and unadjusted univariable odds ratios.

CONCLUSION

Therapy outcome data can be collected quickly and inexpensively using retrospectively self-reported measures in large observational cohorts. Retrospectively self-reported therapy outcomes were associated with four factors previously reported in the literature. Similar data collected in larger observational cohorts may enable detection of novel associations with therapy outcomes, to generate new hypotheses, which can be followed up in prospective studies.

Digital phenotyping in depression diagnostics: Integrating psychiatric and engineering perspectives

Depression is a serious medical condition and is a leading cause of disability worldwide. Current depression diagnostics and assessment has significant limitations due to heterogeneity of clinical presentations, lack of objective assessments, and assessments that rely on patients' perceptions, memory, and recall. Digital phenotyping (DP), especially assessments conducted using mobile health technologies, has the potential to greatly improve accuracy of depression diagnostics by generating objectively measurable endophenotypes. DP includes two primary sources of digital data generated using ecological momentary assessments (EMA), assessments conducted in real-time, in subjects' natural environment. This includes active EMA, data that require active input by the subject, and passive EMA or passive sensing, data passively and automatically collected from subjects' personal digital devices. The raw data is then analyzed using machine learning algorithms to identify behavioral patterns that correlate with patients' clinical status. Preliminary investigations have also shown that linguistic and behavioral clues from social media data and data extracted from the electronic medical records can be used to predict depression status. These other sources of data and recent advances in telepsychiatry can further enhance DP of the depressed patients. Success of DP endeavors depends on critical contributions from both psychiatric and engineering disciplines. The current review integrates important perspectives from both disciplines and discusses parameters for successful interdisciplinary collaborations. A clinically-relevant model for incorporating DP in clinical setting is presented. This model, based on investigations conducted by our group, delineates development of a depression prediction system and its integration in clinical setting to enhance depression diagnostics and inform the clinical decision making process. Benefits, challenges, and opportunities pertaining to clinical integration of DP of depression diagnostics are discussed from interdisciplinary perspectives.

Interpreting patient reports of perceived change during treatment for depression: Findings from the Veterans Outcome Assessment survey

This study addressed ongoing questions about the meaning of patients' perceptions of change during treatment. The study used data from the Veterans Outcome Assessment survey for patients with a depressive disorder, without mental health comorbidities, treated in Department of Veterans Affairs general mental health clinics (n = 694). Perceived changes in problems/symptoms, other domains, and the quality of communication with providers were evaluated with items from the Experience of Care & Health Outcomes (ECHO) survey. Depressive symptoms were measured with the Patient Health Questionnaire-9 (PHQ-9). Linear regression models evaluated associations of perceived change at 3-months post-baseline with observed change in PHQ-9 scores, scores on other patient-reported outcome measures (PROMs), and ratings of communication with providers. Patients' reports of their clinical condition at follow-up together with ratings of communication accounted for approximately one-third of the variance in patients' perceptions of change. Adding change-scores based on baseline and follow-up scores on the PHQ-9 and other PROMs did not improve model fit. The findings suggest that patient reports of perceived change during treatment reflect their current clinical state and their experience of care more closely than actual changes in the PHQ-9 or other PROMs.

Comparison of the sensitivity of patient-reported outcomes for detecting the benefit of biologics in severe asthma

The sensitivity of patient-reported outcomes (PROs) to detect the effects of treatment change depends on the match between the change in items of the PRO and the change that takes place in a sample of people. The aim of this study is to compare the sensitivity of different PROs in detecting changes following the initiation of biologic treatment in asthma. Methods: Patients starting a biologic treatment as part of clinical care completed the Asthma Control Questionnaire (ACQ-6), the Severe Asthma Questionnaire (SAQ and SAQ-global scores) and the EQ5D (EQ-5D-5L and EQ5D-VAS) at baseline. They completed the ACQ-6, SAQ, SAQ-global and a retrospective global rating of change (GRoC) scale at weeks 4, 8 and 16 and completed the EQ-5D-5L and EQ5D-VAS at week 16. The SAQ-global and EQ5D-VAS differ but both are single item 100-point questions. Sensitivity was measured by Cohen’s D effect size at each of the three time points. Results: 110 patients were recruited. Depending on the time of assessment, effect size varied between 0.45 and 0.64 for the SAQ, between 0.50 and 0.77 for the SAQ-global; between 0.45 and 0.69 for ACQ-6; between 0.91 and 1.22 for GRoC; 0.32 for EQ-5D-5L and 0.49 for EQ5D-VAS. Conclusion: The sensitivity to change of a questionnaire varies with the time of measurement. The three asthma-specific prospective measures (SAQ, SAQ-global and ACQ-6) have similar sensitivity to change. The single-item EQ5D-VAS was less sensitive than the asthma specific measures and less sensitive than the single-item SAQ-global. The EQ-5D-5L was least sensitive.

Effective dose 50 method as the minimal clinically important difference: Evidence from depression trials

OBJECTIVE

Previous research on the minimal clinically important difference (MCID) for depression and anxiety is based on population averages. The present study aimed to identify the MCID across the spectrum of baseline severity.

STUDY DESIGN AND SETTINGS

The present analysis used secondary data from 2 randomized controlled trials for depression (n = 1,122) to calibrate the Global Rating of Change with the PHQ-9 and GAD-7. The MCID was defined as a change in scores corresponding to a 50% probability of patients "feeling better", given their baseline severity, referred to as Effective Dose 50 (ED50).

RESULTS

MCID estimates depended on baseline severity and ranged from no change for very mild up to 14 points (52%) on the PHQ-9 and up to 10 points (48%) on the GAD-7 for very high severity. The average MCID estimates were 3.7 points (23%) and 3.3 (28%) for the PHQ-9 and GAD-7 respectively.

CONCLUSION

The ED50 method generates MCID estimates across the spectrum of baseline severity, offering greater precision but at the cost of greater complexity relative to population average estimates. This has important implications for evaluations of treatments and clinical practice where users can use these results to tailor the MCID to specific populations according to baseline severities.

Comparison between self-administered depression questionnaires and patients' own views of changes in their mood: a prospective cohort study in primary care

BACKGROUND

Self-administered questionnaires are widely used in primary care and other clinical settings to assess the severity of depressive symptoms and monitor treatment outcomes. Qualitative studies have found that changes in questionnaire scores might not fully capture patients' experience of changes in their mood but there are no quantitative studies of this issue. We examined the extent to which changes in scores from depression questionnaires disagreed with primary care patients' perceptions of changes in their mood and investigated factors influencing this relationship.

METHODS

Prospective cohort study assessing patients on four occasions, 2 weeks apart. Patients (N = 554) were recruited from primary care surgeries in three UK sites (Bristol, Liverpool and York) and had reported depressive symptoms or low mood in the past year [68% female, mean age 48.3 (s.d. 12.6)]. Main outcome measures were changes in scores on patient health questionnaire (PHQ-9) and beck depression inventory (BDI-II) and the patients' own ratings of change.

RESULTS

There was marked disagreement between clinically important changes in questionnaire scores and patient-rated change, with disagreement of 51% (95% CI 46-55%) on PHQ-9 and 55% (95% CI 51-60%) on BDI-II. Patients with more severe anxiety were less likely, and those with better mental and physical health-related quality of life were more likely, to report feeling better, having controlled for depression scores.

CONCLUSIONS

Our results illustrate the limitations of self-reported depression scales to assess clinical change. Clinicians should be cautious in interpreting changes in questionnaire scores without further clinical assessment.

Patient-reported outcome measures for monitoring primary care patients with depression (PROMDEP): study protocol for a randomised controlled trial

BACKGROUND

Benefits to patients from reduced depression have been shown from monitoring progress with patient-reported outcome measures (PROMs) in psychological therapy and mental health settings. This approach has not yet been researched in the United Kingdom for primary care, which is where most people with depression are treated in the United Kingdom.

METHODS

This is a parallel-group cluster randomised trial with 1:1 allocation to intervention and control. Patients who are age 18+ years, with a new episode of depressive disorder/symptoms, meet the inclusion criteria. Patients with current depression treatment, comorbid dementia/psychosis/substance misuse/suicidal ideas are excluded. The intervention includes the Administration of Patient Health Questionnaire (PHQ-9) as a PROM within 2 weeks of diagnosis and at follow-up 4 weeks later. General practitioners are trained in interpreting scores and asked to take them into account in their treatment decisions. Patients are given written feedback on scores and suggested treatments. The primary outcome measure is Depression on the Beck Depression Inventory BDI-II at 12 weeks. Secondary outcomes include BDI-II at 26 weeks, changes in drug treatments and referrals, social functioning (Work & Social Adjustment Scale) and quality of life (EQ-5D) at 12 and 26 weeks, service use over 26 weeks (modified Client Services Receipt Inventory) to calculate NHS costs, and patient satisfaction at 26 weeks (Medical Informant Satisfaction Scale). The sample includes 676 total participants from 113 practices across three centres. Randomisation is achieved by computerised sequence generation. Blinding is impossible given the nature of the intervention (self-report outcome measures prevent rating bias). Differences at 12 and 26 weeks between intervention and controls in depression, social functioning and quality of life are analysed using linear mixed models, adjusted for socio-demographics, baseline depression, anxiety, and clustering, while including practice as a random effect. Patient satisfaction, quality of life (QALYs) and costs over 26 weeks will be compared between arms. Qualitative process analysis includes interviews with 15-20 GP/NPs and 15-20 patients per arm to reflect trial results and implementation issues, using Normalization Process Theory as a theoretical framework.

DISCUSSION

If PROMs are helpful in improving patient outcomes for depression even to a small extent, then they are likely to be good value for money, given their low cost. The benefits could be considerable, given that depression is common, disabling, and costly.

TRIAL REGISTRATION

ISRCTN no: 17299295. Registered 1st October 2018.

Grant Report on SCH: Personalized Depression Treatment Supported by Mobile Sensor Analytics

We report on the newly started project "SCH: Personalized Depression Treatment Supported by Mobile Sensor Analytics". The current best practice guidelines for treating depression call for close monitoring of patients, and periodically adjusting treatment as needed. This project will advance personalized depression treatment by developing a system, DepWatch, that leverages mobile health technologies and machine learning tools. The objective of DepWatch is to assist clinicians with their decision making process in the management of depression. The project comprises two studies. Phase I collects sensory data and other data, e.g., clinical data, ecological momentary assessments (EMA), tolerability and safety data from 250 adult participants with unstable depression symptomatology initiating depression treatment. The data thus collected will be used to develop and validate assessment and prediction models, which will be incorporated into DepWatch system. In Phase II, three clinicians will use DepWatch to support their clinical decision making process. A total of 128 participants under treatment by the three participating clinicians will be recruited for the study. A number of new machine learning techniques will be developed.

Cognitive testing of the PHQ-9 for depression screening among pregnant and postpartum women in Kenya

BACKGROUND

African women face high rates of depression, particularly during pregnancy or postpartum or after a recent HIV diagnosis. The Patient Health Questionnaire-9 (PHQ-9) depression screening tool has been quantitatively validated and extensively used to identify depression and link individuals to care. However, qualitative work is necessary to identify important opportunities to improve PHQ-9 question comprehension and performance among Kenyan women.

METHODS

We administered the Kiswahili or English PHQ-9 (based on preference) to 29 pregnant and postpartum women in Thika, Kenya. Following administration, we conducted cognitive interviews with a purposive sample of 20 women. We used analytic memos and data matrices to identify themes around scale acceptability, comprehension, and decision and response processes.

RESULTS

Most participants preferred to answer the PHQ-9 in Kiswahili (N = 15; 52%). Among the 20 interview participants, 12 (60%) had scores ≥5, indicating depressive symptoms. Overall, participants found the scale acceptable as an interviewer-administered tool. Participants reported few problems related to comprehension but had difficulty answering items not relevant to their lives (e.g., "watching television") and double-barreled items (e.g., "poor appetite or overeating"). They were hesitant to endorse items related to "duties as a wife and mother" and suicidal ideation. Most participants had difficulty distinguishing between response options of "several days" and "more than half the days".

CONCLUSIONS

We detected several problems related to PHQ-9 comprehension, decision processes, and response processes. We provide recommended changes to instructions and item wording to improve PHQ-9 validity among Kenyan women.

Antidepressant treatment with sertraline for adults with depressive symptoms in primary care: the PANDA research programme including RCT

Background

Despite a growing number of prescriptions for antidepressants (over 70 million in 2018), there is uncertainty about when people with depression might benefit from antidepressant medication and concern that antidepressants are prescribed unnecessarily.

Objectives

The main objective of the PANDA (What are the indications for Prescribing ANtiDepressAnts that will lead to a clinical benefit?) research programme was to provide more guidance about when antidepressants are likely to benefit people with depression. We aimed to estimate the minimal clinically important difference for commonly used self-administered scales for depression and anxiety, and to understand more about how patients respond to such assessments. We carried out an observational study of patients with depressive symptoms and a placebo-controlled randomised controlled trial of sertraline versus placebo to estimate the treatment effect in UK primary care. The hypothesis was that the severity and duration of symptoms were related to treatment response.

Design

The programme consisted of three phases. The first phase relied on the secondary analysis of existing data extracted from published trials. The second phase was the PANDA cohort study of patients with depressive symptoms who presented to primary care and were followed up 2, 4 and 6 weeks after a baseline assessment. Both quantitative and qualitative methods were used in the analysis. The third phase was a multicentre randomised placebo-controlled double-blind trial of sertraline versus placebo in patients presenting to primary care with depressive symptoms.

Setting

UK primary care in Bristol, London, Liverpool and York.

Participants

Patients aged 18–74 years who were experiencing depressive symptoms in primary care. Eligibility for the PANDA randomised controlled trial included that there was uncertainty about the benefits about treatment with an antidepressant.

Interventions

In the PANDA randomised controlled trial, patients were individually randomised to 100 mg daily of sertraline or an identical placebo. The PANDA cohort study was an observational study.

Main outcome measures

Depressive symptoms measured using the Patient Health Questionnaire were the primary outcome for the randomised controlled trial. Other outcomes included anxiety symptoms using the Generalised Anxiety Disorder-7; depressive symptoms using the Beck Depression Inventory, version 2; health-related quality of life; self-reported improvement; and cost-effectiveness.

Results

The secondary analysis of existing randomised controlled trials [GENetic and clinical Predictors Of treatment response in Depression (GenPod), TREAting Depression with physical activity (TREAD) and Clinical effectiveness and cost-effectiveness of cognitive Behavioural Therapy as an adjunct to pharmacotherapy for treatment-resistant depression in primary care (CoBalT)] found evidence that the minimal clinically important difference increased as the initial severity of depressive symptoms rose. Our estimates of minimal clinically important difference were a 17% and 18% reduction in Beck Depression Inventory scores for GenPod and TREAD, respectively. In CoBalT, a 32% reduction corresponded to the minimal clinically important difference but the participants in this study had depression that had not responded to antidepressants. In the PANDA study cohort, and from our analyses in existing data, we found that the minimal clinically important difference varies considerably with the initial severity of depressive and anxiety symptoms. Expressing the minimal clinically important difference as a percentage reduction reduces this variation at higher scores, but at low scores the percentage reduction increased substantially. The results from the qualitative studies pointed out many limitations of the Patient Health Questionnaire-9 items in assessing change and recovery from depression. In the PANDA randomised controlled trial, there was no evidence that sertraline resulted in a reduction in depressive symptoms within 6 weeks of randomisation, but there was some evidence of a reduction by 12 weeks. However, sertraline led to a reduction in anxiety symptoms, an improvement of mental health-related quality of life and an increased likelihood of reporting improvement. The mean Patient Health Questionnaire-9 items score at 6 weeks was 7.98 (standard deviation 5.63) in the sertraline group and 8.76 (standard deviation 5.86) in the placebo group (5% relative reduction, 95% confidence interval –7% to 15%; p = 0.41). Of the secondary outcomes, there was strong evidence that sertraline reduced anxiety symptoms (Generalised Anxiety Disorder-7 score reduced by 17% (95% confidence interval 9% to 25%; p = 0.00005). Sertraline had a high probability (> 90%) of being cost-effective at 12 weeks. The PANDA randomised controlled trial found no evidence that treatment response or cost-effectiveness was related to severity or duration of depressive symptoms. The minimal clinically important difference estimates suggested that sertraline’s effect on anxiety, but not on depression, was likely to be clinically important.

Limitations

The results from the randomised controlled trial and the estimates of minimal clinically important difference were not sufficiently precise to provide specific clinical guidance for individuals. We had low power in testing whether or not initial severity and duration of depressive symptoms are related to treatment response.

Conclusions

The results of the trial support the use of sertraline and probably other selective serotonin reuptake inhibitors because of their action in reducing anxiety symptoms and the likelihood of longer-term benefit on depressive symptoms. Sertraline could be prescribed for anxiety symptoms that commonly occur with depression and many patients will experience a clinical benefit. The Patient Health Questionnaire-9 items and similar self-administered scales should not be used on their own to assess clinical outcome, but should be supplemented with further clinical assessment.

Future work

We need to examine the longer-term effects of antidepressant treatment. We need more precise estimates of the treatment effects and minimal clinically important difference at different severities to provide more specific guidance for individuals. However, the methods we have developed provide an approach towards providing such detailed guidance.

Trial registration

Current Controlled Trials ISRCTN84544741 and EudraCT number 2013-003440-22.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 7, No. 10. See the NIHR Journals Library website for further project information.

The clinical effectiveness of sertraline in primary care and the role of depression severity and duration (PANDA): a pragmatic, double-blind, placebo-controlled randomised trial

BACKGROUND

Depression is usually managed in primary care, but most antidepressant trials are of patients from secondary care mental health services, with eligibility criteria based on diagnosis and severity of depressive symptoms. Antidepressants are now used in a much wider group of people than in previous regulatory trials. We investigated the clinical effectiveness of sertraline in patients in primary care with depressive symptoms ranging from mild to severe and tested the role of severity and duration in treatment response.

METHODS

The PANDA study was a pragmatic, multicentre, double-blind, placebo-controlled randomised trial of patients from 179 primary care surgeries in four UK cities (Bristol, Liverpool, London, and York). We included patients aged 18 to 74 years who had depressive symptoms of any severity or duration in the past 2 years, where there was clinical uncertainty about the benefit of an antidepressant. This strategy was designed to improve the generalisability of our sample to current use of antidepressants within primary care. Patients were randomly assigned (1:1) with a remote computer-generated code to sertraline or placebo, and were stratified by severity, duration, and site with random block length. Patients received one capsule (sertraline 50 mg or placebo orally) daily for one week then two capsules daily for up to 11 weeks, consistent with evidence on optimal dosages for efficacy and acceptability. The primary outcome was depressive symptoms 6 weeks after randomisation, measured by Patient Health Questionnaire, 9-item version (PHQ-9) scores. Secondary outcomes at 2, 6 and 12 weeks were depressive symptoms and remission (PHQ-9 and Beck Depression Inventory-II), generalised anxiety symptoms (Generalised Anxiety Disorder Assessment 7-item version), mental and physical health-related quality of life (12-item Short-Form Health Survey), and self-reported improvement. All analyses compared groups as randomised (intention-to-treat). The study is registered with EudraCT, 2013-003440-22 (protocol number 13/0413; version 6.1) and ISRCTN, ISRCTN84544741, and is closed to new participants.

FINDINGS

Between Jan 1, 2015, and Aug 31, 2017, we recruited and randomly assigned 655 patients-326 (50%) to sertraline and 329 (50%) to placebo. Two patients in the sertraline group did not complete a substantial proportion of the baseline assessment and were excluded, leaving 653 patients in total. Due to attrition, primary outcome analyses were of 550 patients (266 in the sertraline group and 284 in the placebo group; 85% follow-up that did not differ by treatment allocation). We found no evidence that sertraline led to a clinically meaningful reduction in depressive symptoms at 6 weeks. The mean 6-week PHQ-9 score was 7·98 (SD 5·63) in the sertraline group and 8·76 (5·86) in the placebo group (adjusted proportional difference 0·95, 95% CI 0·85-1·07; p=0·41). However, for secondary outcomes, we found evidence that sertraline led to reduced anxiety symptoms, better mental (but not physical) health-related quality of life, and self-reported improvements in mental health. We observed weak evidence that depressive symptoms were reduced by sertraline at 12 weeks. We recorded seven adverse events-four for sertraline and three for placebo, and adverse events did not differ by treatment allocation. Three adverse events were classified as serious-two in the sertraline group and one in the placebo group. One serious adverse event in the sertraline group was classified as possibly related to study medication.

INTERPRETATION

Sertraline is unlikely to reduce depressive symptoms within 6 weeks in primary care but we observed improvements in anxiety, quality of life, and self-rated mental health, which are likely to be clinically important. Our findings support the prescription of SSRI antidepressants in a wider group of participants than previously thought, including those with mild to moderate symptoms who do not meet diagnostic criteria for depression or generalised anxiety disorder.

FUNDING

National Institute for Health Research.