We are currently developing a disease-specific questionnaire to measure quality of life after pulmonary embolism (PE). The aim of this letter is to invite colleagues to cooperate on the validation of our questionnaire.
PE is a rather common disease, with an annual incidence of approximately 0.5 per 1000 persons in Western countries . As PE shares many features with deep vein thrombosis (DVT), both diseases are considered to be different manifestations of the same entity: venous thromboembolism (VTE) . PE and DVT share the same risk factors, such as thrombophilia, pregnancy, cancer, surgery, immobilization, and oral contraceptive use. Furthermore, both manifestations occur in venous blood and coincide frequently [3–5]. Accordingly, treatment recommendations are similar .
PE is a leading cause of mortality and morbidity: death occurs in about 15% of cases within 6 months of its presentation . In addition, VTE often can be considered a chronic disorder: recurrence is common, with an incidence of approximately 30% within 10 years [7,8]. Moreover, residual complaints (known as post-thrombotic syndrome) are reported in 30% of patients with DVT within 2 years after the initial event, despite the use of compression stockings . The most important long-term complication of PE is chronic pulmonary hypertension (which may manifest as fatigue, limited exercise tolerance or shortness of breath), which was shown to affect 3.8% of PE patients within 2 years following the initial event in one study .
Quality of life is conceptualized increasingly as the central outcome of health care. ‘Perceived health, health-related quality of life, and health-state utilities bring health assessment progressively closer to the patient’s perspective’, is a conclusion in a paper by Sullivan on taking the patient’s point of view regarding health care and health into account . To illustrate the gained interest in quality of life, we performed a broad-brush search in Medline with the MeSH term ‘quality of life’. This yielded 7143 articles published in 2007, compared with 4923 in 2002. Surprisingly, a more sophisticated search without any restriction yielded not a single publication on quality of life after PE (neither by a disease generic questionnaire, nor by a disease specific questionnaire). In contrast, quality of life following DVT has been the subject of investigation and several DVT-specific questionnaires have been developed over the past decade [12–16].
We aimed to develop a disease-specific questionnaire to assess quality of life after PE using the principles of grounded theory. We performed qualitative, semi-structured interviews in 10 outpatients (4 males/6 females) whom we selected for the gravity of their complaints following PE. These patients did not have other cardiopulmonary diseases that might have resembled PE-related complaints. Two investigators (LB and EN) visited the subjects at their homes and structured the interviews into social functioning, physical complaints and emotional disturbances. The interviews were tape-recorded with consent and transcribed later. Characteristics of the interviewed patients are listed in Table 1. The most remarkable complaints were shortness of breath/difficulty in breathing, fatigue, fear of recurrence after discontinuing anticoagulant treatment, more readily emotionally disturbed (which bothered a subgroup of the patients) and more social isolation than prior to the PE. The authors (of whom two are experienced clinicians with a specific interest in patients with VTE) remodeled the outcomes of the interviews into the draft questionnaire.
|Gender, age (years), marital status|| |
Main functional complaints
Main psychological complaints
Main social limitations
|1||Female, 37, married||7 months prior to interview. Massive PE, resuscitated||Fatigue, muscle weakness||Anxiety: more readily emotional; fear of recurrent PE; worried about stopping anticoagulant treatment||Afraid of being a burden for relatives and friends, afraid of being alone|
|2||Male, 31, unknown||6 years prior to interview first PE; two recurrences (22 months and 7 months respectively)||Pain behind the shoulder blades, pain in the chest, tiredness, difficulty in breathing||Fear of recurrent PE, more readily emotional (experienced as annoying), depressed||Not able to work, limited in social contacts|
|3||Female, 84, widow||1 year ago PE||Fatigue, not able to exert herself||Depressed (at times)||Becomes easily weary after having a visit from friends/relatives|
|4||Female, 43, married||PE at 13 months and 5 months prior to the interview||Pain in the back and fatigue||Fear of recurrence, depressed feeling, more readily emotional||Avoids visits to friends and shopping in the center of the city, which is too exhausting|
|5||Female, 73, widow||PE 4 years prior to the interview||Breathlessness, sensation of pressure, fatigue||Fear of recurrence||More socially isolated, limited in taking a trip|
|6||Female, 32, single||PE 14 months prior to PE||Difficulty in breathing, pain at the back and between shoulder blades||Anxious about recurrence, worried about stopping anticoagulant treatment||No complaints|
|7||Male, 34, married||PE 4 months prior to interview||Difficulty in breathing, fatigue, shortness of breath, pain behind shoulder blades, chest pain||Fear of recurrence, more readily emotional (which bothers the patient)||Feeling of lack of attention to his children, not able to work, not able to have visitors too often (too exhausting)|
|8||Male, 63, married||PE 13 months prior to interview||Shortness of breath, tired, difficulty in breathing||Much more emotionally disturbed||Not able to perform as much as he intends|
|9||Female, 79, widow||First PE 7 years prior to interview, recurrent PE 6 years||Difficulty in climbing stairs and fatigue, shortness of breath||No typical complaints||No typical complaints|
|10||Male, 55, married||PE 18 months prior to interview||More easily tired, difficulty in breathing following exercise, chest pain||Afraid of a recurrent PE, worried about stopping anticoagulant treatment||Prefers staying at home|
The original version was developed in Dutch. For the creation of the English version, the Dutch version was independently translated by two native English speakers and subsequently back-translated by a third native English speaker. The structure of the questionnaire, which we named PEmb-QoL (Pulmonary Embolism Quality of Life), was modeled in line with the existing generic SF-36 (short form 36) questionnaire and the disease-specific VEINES-QOL/Sym questionnaire, which has been developed for DVT. The PEmb-QoL currently contains 10 questions (40 items) covering six dimensions: frequency of complaints (eight items), activities of daily living (ADL) limitations (13 items), work-related problems (four items), social limitations (one item), intensity of complaints (two items) and emotional complaints (10 items). Two questions provide descriptive information. The PEmb-QoL is a self-administered questionnaire, in line with the SF-36 and Veines-QOL/Sym questionnaires.
Our future aims are to further validate this questionnaire. We are currently distributing the PEmb-QoL questionnaire amongst patients with a recent PE to assess construct validity. The PEmb-QoL questionnaire will be distributed together with the disease generic SF-36 questionnaire to measure its responsiveness. A subgroup of patients with PE will receive the PEmb-QoL a second time for analysis of the test–retest reliability.
At present, it is too early to consider this questionnaire a useful measure. However, to avoid duplication of efforts, we would like to offer the current version of the PEmb-QoL questionnaire to colleagues who are working in this field, in order that it might be further validated.