Skip to main content

Table 2 Summary of the selected studies/papers

From: Relation between health literacy, self-care and adherence to treatment with oral anticoagulants in adults: a narrative systematic review

Author, year. Aim

Methods

Instrument for measuring HL

OAC medication

Risk of Bias (according to ICROMS tool)

Diug, Evans et al. 2011

Evaluate impact of psychosocial factors (social isolation, HL, cognitive abilities) in OAC treatment.

aCase-control study.

Control: Patients with INR in therapeutic range. Cases: previously stabilized patients who registered INR ≥ 6

aSample: 486 patients (157 cases and 329 controls)

aStructured interview of 1 h to identify risk factors. Interview after 30 days.

aData collection:

- Medical history (INR)

- Socio-demographic data

- Comorbidities, cognitive function…

aS-TOFHLA

- Limited HL (0–22 points)

- Adequate HL (23–36 points)

aWarfarin

aPossible Patient memory bias

aNeither interviewers nor patients blinded to obtain cases

ICROMS Score: 24

S1:2; S2:2; S3: 5; S4:2; S5:2; S6:2; S7: 9

Dolor, Ruybalid et al. 2010

Evaluate if home self-control test (PST) improves the quality of anticoagulation and decreases complications

aRandomized Controlled Trial

aSample: 2922 patients.

aTraining to handle PST

aData collection:

- Medical history (INR)

- SPMSQ (Assesses cognitive status)

- ABILHAND (Measure dexterity)

- DASS (Duke anticoagulation satisfaction scale). Quality of life

aREALM Scale

aWarfarin

aOnly Veteran patients with AF or valve replacement (selection bias)

ICROMS Score: 28

S1:2; S2:4; S3:6; S4:6; S5:1; S6:2; S7:7

Estrada, Martin-Hryniewicz et al. 2004

Determine prevalence of low HL in OAC patients and to assess if there is association with anticoagulation control.

aProspective cohort study

aSample: 143 patients.

aData collection:

- Socio-demographic data

- Medical history (dose in mg/week, number of dose changes, number of visits without going, indication of anticoagulation)

- INR: monitoring for 3 months.

- Time Therapeutic Range (TTR)

aVariability of INR was measured by Sigma (INR number, time from the last INR and INR suitable for that patient)

aREALM Scale

aWarfarin

aREALM scale only values reading level, non-comprehension (functional HL)

aOnly English-speaking patients were assessed.

aComplications are not measured.

ICROMS Score: 23

S.1:2; S2:2; S3:5; S4:2; S5:1; S6:2; S7:9

Fang, Machtinger et al. 2006

Assess the association between HL and warfarin knowledge, adherence and control.

aObservational, descriptive study

aSample: 179 patients.

aData collection:

- INR

- S-CASI (Assesses cognitive abilities)

- 4 questions regarding anticoagulation and safe use of warfarin

aINR control every 4–6 weeks.

aAdherence to treatment: last time they forgot to take warfarin, if they forgot 1 dose in the last 2 weeks or in the last 2 days.

aS-TOFHLA

Scale.

- Limited HL (0–22 points)

- Adequate HL (23–36 points)

aWarfarin

aOnly includes patients who speak English or Spanish

aSelf-made questionnaire concerning knowledge of anticoagulation

aSelf-report adherence measure (recall bias)

aComplications are not measured.

ICROMS Score: a

Fang, Panguluri et al. 2009

To assess the relationship between HL and patients with stroke with warfarin to assess perceived information and improve communication.

aObservational, descriptive study

aSample: 183 patients.

aData collection:

- Medical history

- Socio-demographic data

- S-CASI (cognitive abilities)

- Questionnaire of two open questions: why do you take warfarin and what is a stroke? Classification answers: concordant /discordant

aS-TOFHLA

Scale.

- Inadequate HL (0–16)

- marginal HL [17,18,19,20,21,22]

- Adequate HL [23,24,25,26,27,28,29,30,31,32,33,34,35,36]

aWarfarin (For at least 3 months)

aOnly 2 open questions, insufficient to explore subjects’ perception

aRelationship between HL and open-ended questions not validated

aSample obtained in a single center (selection bias)

aOnly patients with stroke

ICROMS Score: -a

Oramasionwu, Bailey et al. 2014

Assess the relationship between HL and anticoagulation control (TTR)

aObservational, descriptive study

aSample: 198 patients.

aData collection:

- Medical history

- INR / TTR

- Socio-demographic data (annual income)

- Questionnaire to evaluate understanding of anticoagulant treatment (Fang et al. 2006)

aS-TOFHLA (36 items of reading comprehension and 4 items of multiple questions of arithmetic). 100 points.

- Limited HL: 0–90

-Adequate HL: 91–100

aWarfarin

aNot assess the appearance of complications.

* Not incorporate factors that could modify INR (diet, other medicines)

*aOnly English-speaking patients were included

ICROMS Score: -a

Schillinger, Machtinger et al. 2006

To relate verbal-visual communication with medication management

aObservational, descriptive study

aSample: 220 patients.

aData collection:

- Medical history (INR)

- S-CASI (Assesses cognitive abilities)

- Number of days they forgot to take warfarin week prior to study

aS-TOFHLA Scale

- Inadequate HL (0–16)

- marginal HL [17,18,19,20,21,22]

- Adequate HL [23,24,25,26,27,28,29,30,31,32,33,34,35,36]

aWarfarin

aReduced sample size

* Method used to determine agreement of treatment (does not determine if visual agreement greater than verbal)

ICROMS Score: a

Schillinger, Wang et al. 2006

To examine if there is a mismatch between the anticoagulant treatment that the patient takes and the standard. Assess adherence

aObservational, descriptive study

aSample: 220 patients.

aData collection:

- Medical history (INR)

a-Adherence (n° of times forgot to take the treatment in 30 days)

aS-CASI (cognitive abilities)

aAgreement of treatment: evaluated concordance of the weekly mg.

aS-TOFHLA (English and Spanish)

- Inadequate HL (0–16)

- marginal HL [17,18,19,20,21,22]

- Adequate HL [23,24,25,26,27,28,29,30,31,32,33,34,35,36]

aWarfarin

aA single clinic is included.

aMeasurement of adherence subject to recall bias and social acceptability bias.

ICROMS Score: a

Wilson, Racine et al. 2003

To investigate the level of HL and to evaluate the readability and cultural sensitivity of the information administered in an anticoagulation clinic

aDescriptive, correlational study

aSample: 65 patients.

aDesigned an easy-to-read aducational/ informative material.

aOnce a week patients were interviewed about diet, medicine control + 15 min. of education for health.

aData collection:

- Medical history (INR)

- Socio-demographic data (annual income)

- Self-made warfarin knowledge questionnaire (20 items)

- SMOG formula (to assess the reading difficulty level of the guide)

aREALM Scale

aWarfarin

aSelf-made questionnaire concerning knowledge of warfarin

aReduced sample size

aDoes not relate INR with HL.

aComplications are not measured.

ICROMS Score: 19

S1:2; S2:2; S3:4; S4:2; S5:0 S6:2; S7: 7

Wilson, Templin et al. 2015

To evaluate the psychometric properties of the KIP-C20 test

aDescriptive, correlational study

aSample: 192 patients.

aCreation KIP-C14 test.

aData collection:

- Socio-demographic data (annual income)

- KIP-C20 test: Knowledge Information Profile-Coumadin.

20 items with response T/F.

2 weeks the KIP-C20 test was administered again.

- Animal Naming Test (ANT): To assess cognitive ability

aREALM Scale

aCoumadin

aUse sample from a single center. (Similar economic level of patients)

aNo complications or adherence to treatment were measured

aLimited to coumadin medicine

ICROMS Score: 21

S1:2; S2:2; S3:4; S4:2; S5:0 S6: 2; S7:9

  1. aThe ICROMS tool does not include the evaluation of observational, descriptive studies