Table 4.
Findings of observational studies of detection rates and factors associated with detection
| Paper | Thresholds for hypertension diagnosis | Outcome of interest | Detection rates | Factors associated with detection (findings with significant P values or outside 95% CIs) |
| Banerjee et al 19 | At least 2 BP readings >140/90 | % of adults (aged >18) with hypertension who had a record of the diagnosis. Two groups investigated: (1) prevalent (those with raised readings and/or on antihypertensives) and (2) incident (new cases during the study period) | 62.9% of hypertensives had a recorded diagnosis (45 365/72 206) among the prevalent group; 19.9% among the incident group (figures not given) | ORs: Prevalent hypertension: age 1.046, women 0.760, Asian 1.67, black/African American 1.979, BMI 1.064, no of BP readings >160/100 1.716Incident hypertension: age 1.030, Asian 1.577, black/African American 2.420, BMI 1.039, no of BP readings >140/90 1.195, no of BP readings >160/100 2.273. |
| Bankart et al 20 | BP >150/90 | Numbers (%) of patients on general practice hypertension registers | 13.3% of the population were on practice hypertension registers, a mean of 750 patients per practice | Predictors of numbers on registers (IRRs): deprivation 1.001, aged >65 10.04, white ethnicity 1.000007, poor health 1.013, practice list size 0.999992, GPs/1000 population 1.06, performance points for hypertension 1.006 |
| de Burgos-Lunar et al 21 | > 140/90 and >130/80 | Correct diagnosis of hypertension defined as the recording of the diagnosis during the first 6 months after the diagnostic criteria were met. Patients had type 2 diabetes; those with hypertension at the time of diagnosis of diabetes were excluded | For those meeting the diagnostic threshold of >140/90 during follow-up, 42.4% remained undiagnosed after a median follow-up of 3.6 years. Mean delay in those diagnosed 8.9 months | OR for correct diagnosis: women 1.288, age 1.006, BMI 25 to 30 1.460, >30 10.696, prior MI 0.448, not depressed 1.630, on antiplatelet treatment 1.469, BP above 140/90 2.770 |
| Byrd et al 22 | > 140/90, or >130/80 in diabetes or chronic kidney disease | Time to recognition of hypertension in patients with an inpatient or outpatient diagnosis for anxiety or depression before first elevated BP | Hypertension recognised within 12 months of second BP reading in 30.1% of those with depression and anxiety, 34.4% of those without | Median days to recognition longer among patients with anxiety and depression (45 days vs 56 days), adjusted HR 1.30 |
| Howes et al 23 | – | Barriers to detection of hypertension in general practice, as perceived by general practitioners | Barriers included: clinical uncertainty about the true BP values, mistrust of the evidence on BP management, patient age, gender and comorbidity, perceived patient attitude, clinical inertia, patient centred care, system issues | |
| Johnson et al 24 | > 140/90 | Patient and provider explanatory variables to identify barriers to hypertension management were based on a model for clinical inertia | Among 10 022 patients with hypertension, 4149 commenced medication or achieved control (41.4%); of the 2606 young adults, 451 (17.3%) received medication before receiving medication | Adjusted HRs of predictors of medication initiation included younger age 0.56, BMI 1.014, stage of hypertension 0.63, diabetes 1.44, having a low prevalence condition 1.26, adjusted clinical risk group score 1.06, no of primary care visits 1.06 |
| MacDonald and Morant25 | > 140/90 | Outcomes were the prevalence and treatment of hypertension (data for 1998, 2003 and 2006) | Among those with hypertension, treatment rates increased from 45.2% (1998), 54.4% (2003), 60.3% (2006) | The likelihood of hypertension being diagnosed and recorded was 2.0 times greater in patients who also had hypercholesterolaemia |
| Mancia et al 26 | > 140/90 | Detection and treatment of hypertension among a sample of patients undergoing a GP check-up | 62.3% of hypertensives were aware of their condition and 58.6% were on drug treatment | Awareness more common in women (67.1% vs 56.9%) and older people (74.3% aged 66 to 75, 43.7% aged 40 to 50). Treatment more common in women (63.6% vs 53.0%) and older people (71.5% aged 66 to 75 vs 39.1% aged 40 to 50) |
| Nazroo et al 27 | >140/90 | The result of BP readings related to the patient reporting they had been diagnosed as having hypertension, or were on antihypertensive medication | Undiagnosed hypertension was present in 12.6% of whites, 12.7% Irish, 9.4% Caribbeans, 9.7% Indians, 6.7% Pakistanis, 5.6% Bangladeshis, 8.2% Chinese | ORs for undiagnosed hypertension: compared with whites, Caribbean 0.43 |
| Pallares-Carratalá et al 28 | > 140/90 | New diagnoses of hypertension in a population without a diagnosis of hypertension who had at least 3 BP readings | Of 48 605 people without a diagnosis of hypertension, 6450 (13.3%) presented diagnostic inertia (raised BP without the diagnosis being made) | Variables associated with diagnostic inertia (ORs): male gender 1.46, atrial fibrillation 0.73, having a health professional 0.88, diabetes 0.93, cardiovascular disease 0.77 and older age 20.4 |
| Patel et al 29 | > 150/90 | High BP on examination, related to recall of a doctor diagnosis of hypertension, or on antihypertensive medication | Of those with raised BP on examination (949), 54.5% (517) recalled being told by a doctor they had high BP, and 35.4% (336) were on antihypertensive treatment | Socioeconomic factors, area of residence, behavioural risk factors not associated with good BP control in either sex, apart from alcohol in men (OR 0.67) |
| Shah and Cook30 | > 160/100 | Antihypertensive medication and control of hypertension among adults found to have raised BP on examination | 1119/2208 (50.7%) hypertensive men and 1620/2811 (57.6%) hypertensive women were receiving antihypertensive medication | In a fully adjusted model, ORs for treatment were as follows: men—younger age 0.39, housing tenure 0.75, living alone 0.49, smoker 0.61, heavy alcohol consumption 0.49, overweight 1.41, family history of heart disease 1.83, lack social support 1.33; women—older age 1.36, family history of heart disease 1.30, obese 1.43, lack social support 1.48 |
| Soljak et al 31 | >150/90 and >140/90 | Numbers of patients on GP hypertension registers (observed prevalence) compared with the modelled (expected) prevalence | The observed prevalence for England was 4 530 369 (8.95%), the expected was 12 356 995 (24.7%) | Regression of expected prevalence plus GP supply gave adjusted correlation coefficient of 0.407 |
| Wallace et al 32 | > 130/80 and >140/90 | The probability of receiving a diagnosis and antihypertensive medication at specific time points | Of 771 people with diabetes and incident hypertension included in the study, 315 (40.9%) received a hypertension diagnosis and 286 (37.1%) received antihypertensives. The median time to diagnosis was 1.9 months | Associations with diagnosis rates (HRs): atrial fibrillation 2.18, peripheral vascular disease 0.18, fewer primary care visits 0.93 |
| Zhao et al 33 | > 140/90 | Age-adjusted prevalence, treatment and control of hypertension | In nine ethnic groups, prevalence varied in women from 30.0% to 59.1%, treatment rates varying from 64.6% to 77.8% Figures for men: prevalence 35.9%–59.9%, treatment 57.0%–70.9% | Compared with whites, hypertension treatment was more likely in Asian Indians (women/men) OR 1.25, 1.17; Chinese 1.38, 1.34; Filipinos 1.97, 1.64; Japanese 1.32, 1.29; Vietnamese 1.40, n.s.; and Non-Hispanic Black 1.92, 1.72 |
BMI, body mass index; BP, blood pressure; GP, general practitioner; IRR, incident rate ratio; MI, myocardial infarction; n.s., not significant.