What is the Quality of Life in Depression Scale?

Introduction

The Quality of Life In Depression Scale (QLDS), originally proposed by Sonja Hunt and Stephen McKenna, is a disease specific patient-reported outcome which assesses the impact that depression has on a patient’s quality of life. It is the most commonly used measure of quality of life in clinical trials and studies of depression. The QLDS was developed as a measure to be used in future clinical trials of anti-depressant therapy.

It is a 34 item self-rated questionnaire which consists of dichotomous response questions, with the response being either True/Not True. It is scored binomially (0-1) with higher scores on the QLDS indicating a lower quality of life. Several tests of construct validity and internal consistency have found the QLDS to be a good measure of quality of life.

Needs-based Model

The QLDS is built around the generally accepted assumption that one’s quality of life can only be assessed subjectively. Quality of life tends to be greatly influenced by factors such as depression, anxiety, tension or fatigue.

The QLDS is based around the needs-based model of quality of life. This is derived from the assumption that quality of life is dependent on a person’s ability to fulfil particular human needs. The QLDS questions centre around a number of needs that were considered crucial in order to suffice a high quality of life. These include but are not limited to; food, sleep, sex, safety, love, enjoyment, self-esteem and self-actualisation.

The QLDS uses a two-point response system with either True or Not True. The high number of items in the questionnaire allows the detection of moderately minor changes in quality of life.

Items on the QLDS are given a score of 1 when the question is applicable to the respondent and 0 when it is not applicable. The items are totalled to give a score ranging from 0-34. Low scores act as an indicator towards a high quality of life.

Development

The QLDS was developed by Galen Research in 1992 and was funded by Lilly Industries. It was developed in the United Kingdom in conjunction with the Netherlands. The QLDS was the first quality of life instrument to be developed in 2 languages simultaneously. The development of the QLDS coincided with a rising interest on the impact of illness and its treatment on the quality of life of the patient. McKenna and Hunt constructed the QLDS on the basis of providing a measure for this, as well as attempting to overcome contemporary studies concerning low correlations between patient self-assessment and nurse or therapist evaluations.

The items in the UK English QLDS were derived from statements made in qualitative interviews by 30 depressed or recently recovered patients based in the North West of England and Scotland. Interviews took a conversational approach and lasted between 30 minutes to 2 hours. Interviewees were between the age range of 19-64 years, with 22 females and 8 males. After a refinement process, based on categories of needs proposed by McKenna and Hunt, 426 relevant statements were derived from the interview transcripts. Upon further examination they produced 41 statements for an initial questionnaire.

A further 35 patients were asked to complete the draft questionnaire and review their experience with it. They were composed of 22 females and 13 males in the age range of 24-72 years. Interviewees expressed a great degree of approval with the questionnaire, although a few mentioned how the binomial system caused difficulty, as it required them to make complete choices.

Following this, the questionnaire was revised to 34 items and field tested to determine construct validity and reliability.

International Development

The first two languages the QLDS was available in were UK English and Dutch. These were shown to have good reliability, validity and responsiveness. In 1999, McKenna in collaboration with a team of international researchers developed and tested the QLDS in 9 new languages. This involved translation, followed by field testing for content validity and the new measure’s construct validity.

Across the majority of translations, no major difficulties arose excluding Morocco. Cultural differences between Morocco and the UK provided challenge, alongside a lack of literal equivalents between the two languages. An example of this is the absence of an equivalent for the verb ‘to enjoy’ in Arabic. Researchers also faced further difficulty due to the contemporarily high rate of illiteracy, as the test could not be self-administrative on as large a scale as anticipated. As a result, although the data demonstrated both reliability and construct validity, they were unable to place confidence in the Arabic adaptation’s equivalence to the other developed versions.

Reliability, Validity and Responsiveness

Testing the Anglo-Dutch Project

Following the collaborative Anglo-Dutch project, researchers had to compare the QLDS’ success with established measures of the same concept. No measure of quality of life in depression was available so both versions had to be matched to related measures. In the UK this was the General Well-Being Index (GWBI) whilst in the Netherlands the Sickness Impact Profile (PS-SIP) acted as a comparison.

Reliability and Internal Consistency

For use in a clinical trial, an instrument like the QLDS should have a test-retest reliability coefficient of minimum 0.85. Internal consistency also requires a minimum of 0.85 and is assessed using Cronbach’s alpha-coefficient.

In the UK, the test-retest correlation coefficient for patients with stable depression was 0.94 (n=37). The test-retest correlation coefficient in the Netherlands was 0.87 (n=33).

For internal consistency the UK recorded a value of 0.95 and the Netherlands a value of 0.92. These results suggested the QLDS produced a low degree of measurement error and high internal consistency.

Content and Construct Validity

No missing items applicable to participants were recognised. The relevancy and ease of completion indicated by field-test interviews suggested the high content validity of the QLDS.

The QLDS and GWBI had a correlation score of 0.79 in the UK (n=65). The Dutch adaptation had a correlation of 0.71 with the PS-SIP (n=77). These measurements were anticipated to be slightly lower due to the difference of purpose between measures.

Responsiveness

The QLDS’ responsiveness was analysed in a general practice population of 540 patients with major depression. Over a 6-month period, substantial progress in the level of depression was seen.

8 weeks into treatment the mean QLDS score rose by 68%, with patients who continued treatment for the full 6-months recording an increase of 78%. The QLDS was concluded by the researchers to be responsive to change in quality of life throughout successful pharmacological depression treatment.

International Use

Since its development, the QLDS has been adapted and validated in 17 languages other than UK English, including Norwegian, Spanish, Danish, French, German and Italian. This has allowed the QLDS to be used in research and clinical studies worldwide.

Studies utilising the QLDS include investigations into venlafaxine, duloxetine and bupropion.

Refer to Beck Depression Inventory, Beck Anxiety Inventory, Beck Hopelessness Scale, Major Depression Inventory.

What is the Major Depression Inventory?

Introduction

The Major Depression Inventory (MDI) is a self-report mood questionnaire developed by the World Health Organisation. The instrument was constructed by a team led by Professor Per Bech, a psychiatrist based at Frederiksborg General Hospital in Denmark. The MDI differs from many other self-report inventories, such as the Beck Depression Inventory (BDI), because it is able to generate an ICD-10 or DSM-IV diagnosis of clinical depression in addition to an estimate of symptom severity.

Unlike many other similar instruments, the MDI is available free of charge and can be downloaded from the internet with a full manual and scoring instructions. This makes it an attractive option in epidemiological population surveys. It has also been translated into seven languages.

Scoring

To measure treatment outcome the sum of the ten items is used. A higher score signifies deeper depression.

When using the scale to diagnose depression according to ICD-10, there are the following possibilities:

  • Mild depression:
    • A score of 4 or 5 in two of the first three items.
    • Plus a score of at least 3 on two or three of the last seven items.
  • Moderate depression:
    • A score of 4 or 5 in two or three of the first three items.
    • Plus a score of at least 3 on four of the last seven items.
  • Severe depression:
    • A score of 4 or 5 in all of the first three items.
    • Plus a score of at least 3 on five or more of the last seven items.
  • Major depression:
    • The number of items is reduced to nine, as Item 4 is part of Item 5.
    • Include whichever of the two items has the highest score (item 4 or 5).
    • A score on at least five items is required, to be scored as follows:
      • The score on the first three items must be at least 4, and on the other items at least 3.
      • Either Item 1 or 2 must have a score of 4 or 5.

Refer to Beck Anxiety Inventory, Beck Depression Inventory, Beck Hopelessness Scale, and Quality of Life in Depression Scale.

What is the Beck Hopelessness Scale?

Introduction

The Beck Hopelessness Scale (BHS) is a 20-item self-report inventory developed by Dr. Aaron T. Beck that was designed to measure three major aspects of hopelessness:

  • Feelings about the future;
  • Loss of motivation; and
  • Expectations.

The test is designed for adults, age 17-80. It measures the extent of the respondent’s negative attitudes, or pessimism, about the future. It may be used as an indicator of suicidal risk in depressed people who have made suicide attempts. The test is multiple choice. It is not designed for use as a measure of the hopelessness construct but has been used as such. Sufficient data about the use of the test with those younger than 17 has not been collected. It may be administered and scored by paraprofessionals, but must be used and interpreted only by clinically trained professionals, who can employ psychotherapeutic interventions. Norms are available for suicidal patients, depressed patients, and drug abusers.

Reliability and Validity

The BHS moderately correlates with the Beck Depression Inventory, although research shows that the BDI is better suited for predicting suicidal ideation behaviour. The internal reliability coefficients are reasonably high (Pearson r = 0.82 to 0.93 in seven norm groups), but the BHS test-retest reliability coefficients are modest (0.69 after one week and 0.66 after six weeks).

Dowd and Owen both positively reviewed the effectiveness of the instrument, with Dowd concluding that the BHS was “a well-constructed and validated instrument, with adequate reliability”.

DMCA Notice

In 2012 the scale became the subject of a much circulated DMCA notice that resulted in the temporary shutdown of 1.45 million education blogs due to the scale’s inclusion in a single blog several years prior to the incident, sparking widespread indignation.

Beck Hopelessness Scale is sold as a product by Pearson, along with the Beck Anxiety Inventory (BAI) and the Beck Depression Inventory II (BDI-II).

Questionnaire

The Beck Hopelessness Scale questionnaire consists of twenty true/false questions examining the respondent’s attitude for the past week, such as:

  • I might as well give up because there’s nothing I can do to make things better for me.
  • I happen to be particularly lucky and I expect to get more of the good things in life than the average person.
  • I never get what I want, so it’s foolish to want anything.
  • My past experiences have prepared me well for my future.

Refer to Beck Anxiety Inventory, Beck Depression Inventory, Major Depression Inventory, and Quality of Life in Depression Scale.

What is the Beck Anxiety Inventory?

Introduction

The Beck Anxiety Inventory (BAI), created by Aaron T. Beck and other colleagues, is a 21-question multiple-choice self-report inventory that is used for measuring the severity of anxiety in children and adults. The questions used in this measure ask about common symptoms of anxiety that the subject has had during the past week (including the day you take it) (such as numbness and tingling, sweating not due to heat, and fear of the worst happening). It is designed for individuals who are of 17 years of age or older and takes 5 to 10 minutes to complete. Several studies have found the Beck Anxiety Inventory to be an accurate measure of anxiety symptoms in children and adults.

The BAI contains 21 questions, each answer being scored on a scale value of 0 (not at all) to 3 (severely). Higher total scores indicate more severe anxiety symptoms. The standardised cutoffs are:

  • 0-7: Minimal.
  • 8-15: Mild.
  • 16-25: Moderate.
  • 26-63: Severe.

The BAI has been criticised for its predominant focus on physical symptoms of anxiety (most akin to a panic response). As such, it is often paired with the Penn State Worry Questionnaire, which provides a more accurate assessment of the cognitive components of anxiety (i.e. worry, catastrophising, etc.) commonly seen in generalised anxiety disorder.

Two Factor Approach to Anxiety

Though anxiety can be thought of as having several components, including cognitive, somatic, affective, and behavioural components, Beck et al. included only two components in the BAI’s original proposal: cognitive and somatic. The cognitive subscale provides a measure of fearful thoughts and impaired cognitive functioning, and the somatic subscale measures the symptoms of physiological arousal.

Since the introduction of the BAI, other factor structures have been implemented, including a four factor structure used by Beck and Steer with anxious outpatients that included neurophysiological, autonomic symptoms, subjective, and panic components of anxiety. In 1993, Beck, Steer, and Beck used a three factor structure including subjective, somatic, and panic subscale scores to differentiate among a sample of clinically anxious outpatients.

Because the somatic subscale is emphasized on the BAI, with 15 out of 21 items measuring physiological symptoms, perhaps the cognitive, affective, and behavioural components of anxiety are being deemphasized. Therefore, the BAI functions more adequately in anxiety disorders with a high somatic component, such as panic disorder. On the other hand, the BAI will not function as adequately for disorders such as social phobia or obsessive-compulsive disorder, which have a stronger cognitive or behavioural component.

Clinical Use

The BAI was specifically designed as “an inventory for measuring clinical anxiety” that minimizes the overlap between depression and anxiety scales. While several studies have shown that anxiety measures, including the State-Trait Anxiety Inventory (STAI), are either highly correlated or indistinguishable from depression, the BAI is shown to be less contaminated by depressive content.

Since the BAI does only questions symptoms occurring over the last week, it is not a measure of trait anxiety or state anxiety. The BAI can be described as a measure of “prolonged state anxiety”, which, in a clinical setting, is an important assessment. A version of the BAI, the Beck Anxiety Inventory-Trait (BAIT), was developed in 2008 to assess trait anxiety rather than immediate or prolonged state anxiety, much like the STAI. However, unlike the STAI, the BAIT was developed to minimize the overlap between anxiety and depression.

A 1999 review found that the BAI was the third most used research measure of anxiety, behind the STAI and the Fear Survey Schedule, which provides quantitative information about how clients react to possible sources of maladaptive emotional reactions.

The BAI has been used in a variety of different patient groups, including adolescents. Though support exists for using the BAI with high-school students and psychiatric inpatient samples of ages 14 to 18 years, the recently developed diagnostic tool, Beck Youth Inventories, Second Edition, contains an anxiety inventory of 20 questions specifically designed for children and adolescents ages 7 to 18 years old.

Limitations

Though the BAI was developed to minimise its overlap with the depression scale as measured by the Beck Depression Inventory, a correlation of r=.66 (p<.01) between the BAI and BDI-II was seen among psychiatric outpatients, suggesting that the BAI and the BDI-II equally discriminate between anxiety and depression.

Another study indicates that, in primary care patients with different anxiety disorders including social phobia, panic disorder, panic disorder with or without agoraphobia, agoraphobia, or generalised anxiety disorder, the BAI seemed to measure the severity of depression. This suggests that perhaps the BAI cannot adequately differentiate between depression and anxiety in a primary care population.

In a study examining the BAI’s use on older adults with generalised anxiety disorder, no discriminant validity was seen between the BAI and measures of depression. This could perhaps be due to the increased difficulty in discriminating between anxiety and depression in older adults due to “de-differentiation” of the symptoms of anxiety with the aging process, as hypothesized by Krasucki et al.

Many questions of the Beck Anxiety Inventory include physiological symptoms, such as palpitations, indigestion, and trouble breathing. Because of this, it has been shown to elevate anxiety measures in those with physical illnesses like postural orthostatic tachycardia syndrome, when the Anxiety Sensitivity Index did not.

Finally, the mean and median reliability estimates of the BAI tend to be lower when given to a nonpsychiatric population, such as college students, than when given to a psychiatric population.

Refer to Beck Depression Inventory, Beck Hopelessness Scale, Major Depression Inventory, and Quality of Life in Depression Scale.

What is the Beck Depression Inventory?

Introduction

The Beck Depression Inventory (BDI, BDI-1A, BDI-II), created by Aaron T. Beck, is a 21-question multiple-choice self-report inventory, one of the most widely used psychometric tests for measuring the severity of depression. Its development marked a shift among mental health professionals, who had until then, viewed depression from a psychodynamic perspective, instead of it being rooted in the patient’s own thoughts.

In its current version, the BDI-II is designed for individuals aged 13 and over, and is composed of items relating to symptoms of depression such as hopelessness and irritability, cognitions such as guilt or feelings of being punished, as well as physical symptoms such as fatigue, weight loss, and lack of interest in sex.

There are three versions of the BDI – the original BDI, first published in 1961 and later revised in 1978 as the BDI-1A, and the BDI-II, published in 1996. The BDI is widely used as an assessment tool by health care professionals and researchers in a variety of settings.

The BDI was used as a model for the development of the Children’s Depression Inventory (CDI), first published in 1979 by clinical psychologist Maria Kovacs.

Brief History

According to Beck’s publisher, ‘When Beck began studying depression in the 1950s, the prevailing psychoanalytic theory attributed the syndrome to inverted hostility against the self.’ By contrast, the BDI was developed in a novel way for its time; by collating patients’ verbatim descriptions of their symptoms and then using these to structure a scale which could reflect the intensity or severity of a given symptom.

Beck drew attention to the importance of “negative cognitions” described as sustained, inaccurate, and often intrusive negative thoughts about the self. In his view, it was the case that these cognitions caused depression, rather than being generated by depression.

Beck developed a triad of negative cognitions about the world, the future, and the self, which play a major role in depression. An example of the triad in action taken from Brown (1995) is the case of a student obtaining poor exam results:

  • The student has negative thoughts about the world, so he may come to believe he does not enjoy the class.
  • The student has negative thoughts about his future because he thinks he may not pass the class.
  • The student has negative thoughts about his self, as he may feel he does not deserve to be in college.

The development of the BDI reflects that in its structure, with items such as “I have lost all of my interest in other people” to reflect the world, “I feel discouraged about the future” to reflect the future, and “I blame myself for everything bad that happens” to reflect the self. The view of depression as sustained by intrusive negative cognitions has had particular application in cognitive behavioural therapy (CBT), which aims to challenge and neutralise them through techniques such as cognitive restructuring.

BDI

The original BDI, first published in 1961, consisted of twenty-one questions about how the subject has been feeling in the last week. Each question had a set of at least four possible responses, ranging in intensity. For example:

  • (0) I do not feel sad.
  • (1) I feel sad.
  • (2) I am sad all the time and I can’t snap out of it.
  • (3) I am so sad or unhappy that I can’t stand it.

When the test is scored, a value of 0 to 3 is assigned for each answer and then the total score is compared to a key to determine the depression’s severity. The standard cut-off scores were as follows:

  • 0-9: indicates minimal depression.
  • 10-18: indicates mild depression.
  • 19-29: indicates moderate depression.
  • 30-63: indicates severe depression.

Higher total scores indicate more severe depressive symptoms.

Some items on the original BDI had more than one statement marked with the same score. For instance, there are two responses under the Mood heading that score a 2:

  • (2a) “I am blue or sad all the time and I can’t snap out of it” and
  • (2b) “I am so sad or unhappy that it is very painful”.

BDI-IA

The BDI-IA was a revision of the original instrument developed by Beck during the 1970s, and copyrighted in 1978. To improve ease of use, the “a and b statements” described above were removed, and respondents were instructed to endorse how they had been feeling during the preceding two weeks. The internal consistency for the BDI-IA was good, with a Cronbach’s alpha coefficient of around 0.85, meaning that the items on the inventory are highly correlated with each other.

However, this version retained some flaws; the BDI-IA only addressed six out of the nine DSM-III criteria for depression. This and other criticisms were addressed in the BDI-II.

BDI-II

The BDI-II was a 1996 revision of the BDI, developed in response to the American Psychiatric Association’s publication of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, which changed many of the diagnostic criteria for Major Depressive Disorder.

Items involving changes in body image, hypochondriasis, and difficulty working were replaced. Also, sleep loss and appetite loss items were revised to assess both increases and decreases in sleep and appetite. All but three of the items were reworded; only the items dealing with feelings of being punished, thoughts about suicide, and interest in sex remained the same. Finally, participants were asked to rate how they have been feeling for the past two weeks, as opposed to the past week as in the original BDI.

Like the BDI, the BDI-II also contains 21 questions, each answer being scored on a scale value of 0 to 3. Higher total scores indicate more severe depressive symptoms. The standardized cutoffs used differ from the original:

  • 0-13: minimal depression.
  • 14-19: mild depression.
  • 20-28: moderate depression.
  • 29-63: severe depression.

One measure of an instrument’s usefulness is to see how closely it agrees with another similar instrument that has been validated against information from a clinical interview by a trained clinician. In this respect, the BDI-II is positively correlated with the Hamilton Depression Rating Scale with a Pearson r of 0.71, showing good agreement. The test was also shown to have a high one-week test–retest reliability (Pearson r =0.93), suggesting that it was not overly sensitive to daily variations in mood. The test also has high internal consistency (α=.91).

Impact

The development of the BDI was an important event in psychiatry and psychology; it represented a shift in health care professionals’ view of depression from a Freudian, psychodynamic perspective, to one guided by the patient’s own thoughts or “cognitions”. It also established the principle that instead of attempting to develop a psychometric tool based on a possibly invalid theory, self-report questionnaires when analysed using techniques such as factor analysis can suggest theoretical constructs.

The BDI was originally developed to provide a quantitative assessment of the intensity of depression. Because it is designed to reflect the depth of depression, it can monitor changes over time and provide an objective measure for judging improvement and the effectiveness or otherwise of treatment methods. The instrument remains widely used in research; in 1998, it had been used in over 2000 empirical studies. It has been translated into multiple European languages as well as Arabic, Chinese, Japanese, Persian, and Xhosa.

Limitations

The BDI suffers from the same problems as other self-report inventories, in that scores can be easily exaggerated or minimized by the person completing them. Like all questionnaires, the way the instrument is administered can have an effect on the final score. If a patient is asked to fill out the form in front of other people in a clinical environment, for instance, social expectations have been shown to elicit a different response compared to administration via a postal survey.

In participants with concomitant physical illness the BDI’s reliance on physical symptoms such as fatigue may artificially inflate scores due to symptoms of the illness, rather than of depression. In an effort to deal with this concern Beck and his colleagues developed the “Beck Depression Inventory for Primary Care” (BDI-PC), a short screening scale consisting of seven items from the BDI-II considered to be independent of physical function. Unlike the standard BDI, the BDI-PC produces only a binary outcome of “not depressed” or “depressed” for patients above a cutoff score of 4.

Although designed as a screening device rather than a diagnostic tool, the BDI is sometimes used by health care providers to reach a quick diagnosis.

The BDI is copyrighted; a fee must be paid for each copy used. There is no evidence that the BDI-II is more valid or reliable than other depression scales, and public domain scales such as the Patient Health Questionnaire – Nine Item (PHQ-9) have been studied as a useful tool.

Refer to Beck Anxiety Inventory, Beck Hopelessness Scale, Major Depression Inventory, and Quality of Life in Depression Scale.